  # Problem Solving - Percent

by Mary
(Brooklyn, New york )

1- On friday and saturday, there were a total of 200 cars in the parking lot of a movie theater. On friday, 120 cars were in the parking lot.
a. What percent of the total number of cars were in the parking lot on friday? show work
b. what percent of total numbers of cars were in teh parking lot on saturday? show work

2- charles stores his baseball cards in a container like the one shown below.

I am not able to attach the diagram but it's height is 5 in. lenght is 9 in. and width is 3 in.

a. what is the volume, in cubic inches, of the container? show work

3- christina scored a certain number of goals, g, during a soccer season. Sarah scored twice as many goals during the same season.

a.Write an expression for the nubmer of goals sarah scored.
b. explain how you determined your expression.

4- JOrdan has a bag that contains 246 marbles. There are 51 brown marbles adn 195 gray marbles.

a. Estimate teh percent of brown marbles in the bag.

use words, symbols, or nubmer to explain how to esitmate the percent of brown marbles in the bag.

b. Jordan adds 12 red marbles to the bag. Estimate the percent of marbles in teh bag that are red. show work

5- The name jalen is writeen on a piece of paper. The paper is then ripped into 5 pieces, with each piece having a letter on it. Answer the following question about prbability:
a) P("A")= b) P(VOWEL)= C) P(NOT A VOWEL)=

D)What percent of the time woud you expect to randomly choose the letter "L"?
E)What percent of the time would you expect to randomly choose the letter "J" or"E"?

6- Leon uses the digits 5, 9, and 7 to creat as many 3-digit numbers. Each number is written on a piece of paper and puit into a hat.
a. what's the probability of randomly selecting a nubme rthat begins with the digit 9?
b. wht's percent of the time would you expect to choose a number that starts with eithe ra 5 or 9?

7- Mr. Rosenberg has a container of 80 pencils in his drawer. Half of the pencils are wooden. Out of the menchanical pencils, 20 are red, 10 are blue, adn 10 are green.
a. If Mr. Rosenberg randomly takes a pencil out of the container, what is the probability that the pencil will be wooden? Explain how you got your answer.

b. If Mr. Rosenberg randomly takes a pencil out of the container, what is teh probability that the pencil will be blue or green? Explain how you got your answer.

Thank you so much for you help. I would really appreciate it.

### Comments for Problem Solving - Percent

 May 12, 2011 Problem Solving – Percent - Probability by: Staff ------------------------------------------ Part IV d) What percent of the time would you expect to randomly choose the letter "L"? P("L") = (number of times the “L” appears in the name)/(total number of letters in the name) P("L") = (1)/(5) P("L") = 1/5 To convert the fraction to a %, multiply by 100 P("L") = (1/5)*100 P("L") = 100/5 P("L") = 20% The final answer to Problem 5, Part d is: 20% e) What percent of the time would you expect to randomly choose the letter "J" or "E"? P("J or E") = (number of times the “J” + number of times “E” appears in the name)/(total number of letters in the name) P("J or E ") = (1 + 1)/(5) P("J or E ") = (2)/(5) P("J or E ") = 2/5 To convert the fraction to a %, multiply by 100 P("J or E ") = (2/5)*100 P("J or E ") = 200/5 P("J or E ") = 40% The final answer to Problem 5, Part e is: 40% 6- Leon uses the digits 5, 9, and 7 to create as many 3-digit numbers. Each number is written on a piece of paper and put into a hat. a. What's the probability of randomly selecting a number that begins with the digit 9? P("9") = (number of times the “9” appears within the three digits)/(total number of digits) P("9") = (1)/(3) P("9") = 1/3 The final answer to Problem 6, Part a is: 1/3 b. What percent of the time would you expect to choose a number that starts with either a 5 or 9? P("5 or 9") = (number of times the “5” + number of times “9” is written)/(total number of digits) P("5 or 9") = (1 + 1)/(3) P("5 or 9") = (2)/(3) P("5 or 9") = 2/3 To convert the fraction to a %, multiply by 100 P("5 or 9") = (2/3)*100 P("5 or 9") = 200/3 P("5 or 9") = 66.7% The final answer to Problem 6, Part b is: 66.7% 7- Mr. Rosenberg has a container of 80 pencils in his drawer. Half of the pencils are wooden. Out of the mechanical pencils, 20 are red, 10 are blue, and 10 are green. a. If Mr. Rosenberg randomly takes a pencil out of the container, what is the probability that the pencil will be wooden? Explain how you got your answer. P("wooden") = (number of wooden pencils)/(total number of pencils) P("wooden") = (40)/(80) P("wooden") = 1/2 The final answer to Problem 7, Part a is: 1/2 b. If Mr. Rosenberg randomly takes a pencil out of the container, what is the probability that the pencil will be blue or green? Explain how you got your answer. P("blue or green") = (number of “blue” pencils + number of “green” pencils)/(total number of pencils) P("blue or green") = (10 + 10)/(80) P("blue or green") = (20)/(80) P("blue or green") = 1/4 The final answer to Problem 7, Part b is: 1/4 Thanks for writing. Staff www.solving-math-problems.com

 May 12, 2011 Problem Solving – Percent - Probability by: Staff ------------------------------------------ Part III 4- Jordan has a bag that contains 246 marbles. There are 51 brown marbles and 195 gray marbles. a. Estimate the percent of brown marbles in the bag. Use words, symbols, or number to explain how to estimate the percent of brown marbles in the bag. fraction of brown marbles = (number of brown marbles)/(total number of marbles) fraction of brown marbles = (51 brown marbles)/(246 marbles) fraction of brown marbles = 51/246 decimal equivalent = 0.207317 To convert the decimal equivalent to a %, multiply by 100 % of brown marbles = (0.207317)*100 % of brown marbles = 20.7% The final answer to Problem 4, Part a is: 20.7%. However, the question asks you to estimate the % of brown marbles (estimate, not calculate). You could say that 51 brown marbles is about 1/5 of the total number of marbles. 1/5 = 20%. So you would estimate the % of brown marbles at about 20%. b. Jordan adds 12 red marbles to the bag. Estimate the percent of marbles in the bag that are red. Show work fraction of red marbles = (number of red marbles)/(total number of old marbles + 12 red marbles) fraction of red marbles = (12)/(246 + 12) fraction of red marbles = (12)/(258) fraction of red marbles = 12/258 fraction of red marbles = 2/43 decimal equivalent = 0.0465116 To convert the decimal equivalent to a %, multiply by 100 % of red marbles = (0.0465116)*100 % of red marbles = 4.6% The final answer to Problem 4, Part b is: 4.6%. However, this question also asks you to estimate the % of red marbles (estimate, not calculate). You could say that 12 red marbles is about 1/20 of the total number of marbles (since 20*12=240. 240 is a number close to 258, the total number of marbles). 1/20 = 5%. So you would estimate the % of red marbles at about 5%. 5- The name Jalen is written on a piece of paper. The paper is then ripped into 5 pieces, with each piece having a letter on it. Answer the following question about probability: a) P("A")= P("A") = (number of times the “A” appears in the name)/(total number of letters in the name) P("A") = (1)/(5) P("A") = 1/5 The final answer to Problem 5, Part a is: 1/5 b) P(VOWEL)= there are two vowels in the name Jalen P(VOWEL) = (number of times a vowel appears in the name)/(total number of letters in the name) P(VOWEL) = (2)/(5) P(VOWEL) = 2/5 The final answer to Problem 5, Part b is: 2/5 c) P(NOT A VOWEL)= letters which are not a vowels in the name Jalen = 5 - 2 = 3 P(NOT A VOWEL) = (number of times a non-vowel appears in the name)/(total number of letters in the name) P(NOT A VOWEL) = (3)/(5) P(NOT A VOWEL) = 3/5 The final answer to Problem 5, Part c is: 3/5 ------------------------------------------

 May 12, 2011 Problem Solving – Percent - Probability by: Staff -------------------------------------------------------------- Part II The answer: 1- On Friday and Saturday, there were a total of 200 cars in the parking lot of a movie theater. On Friday, 120 cars were in the parking lot. a. What percent of the total number of cars were in the parking lot on Friday? Show work Friday fraction of cars = (Friday Cars)/(Friday Cars + Saturday Cars) Friday fraction of cars = (120 Cars)/(200 Cars) Friday fraction of cars = 3/5 To convert the fraction of cars to a %, multiply by 100 Friday % of cars = (3/5)*100 Friday % of cars = 60% The final answer to Problem 1, Part a is: 60% b. what percent of total numbers of cars were in the parking lot on Saturday? Show work Saturday % of cars = 100% - Friday % Saturday % of cars = 100% - 60 % Saturday % of cars = 40 % The final answer to Problem 1, Part b is: 40% 2- Charles stores his baseball cards in a container like the one shown below. I am not able to attach the diagram but its height is 5 in. length is 9 in. and width is 3 in. a. What is the volume, in cubic inches, of the container? Show work volume = length * width * height volume = 9 in * 3 in * 5 in volume = 135 in³ (135 cubic inches) The final answer to Problem 2, Part a is: 135 cubic inches 3- Christina scored a certain number of goals, g, during a soccer season. Sarah scored twice as many goals during the same season. a. Write an expression for the number of goals Sarah scored. number of goals Christina scored = g number of goals Sarah scored = 2 * (number of goals Christina scored) number of goals Sarah scored = 2 * g = 2g The final answer to Problem 3, Part a is: number of goals Sarah scored = 2g b. Explain how you determined your expression. See part a ------------------------------------------

 May 12, 2011 Problem Solving – Percent - Probability by: Staff Part I The question: by Mary (Brooklyn, New York ) Can you please help with the following question: 1- On friday and saturday, there were a total of 200 cars in the parking lot of a movie theater. On friday, 120 cars were in the parking lot. a. What percent of the total number of cars were in the parking lot on friday? show work b. what percent of total numbers of cars were in teh parking lot on saturday? show work 2- charles stores his baseball cards in a container like the one shown below. I am not able to attach the diagram but its height is 5 in. lenght is 9 in. and width is 3 in. a. what is the volume, in cubic inches, of the container? show work 3- christina scored a certain number of goals, g, during a soccer season. Sarah scored twice as many goals during the same season. a.Write an expression for the nubmer of goals sarah scored. b. explain how you determined your expression. 4- JOrdan has a bag that contains 246 marbles. There are 51 brown marbles adn 195 gray marbles. a. Estimate teh percent of brown marbles in the bag. use words, symbols, or nubmer to explain how to esitmate the percent of brown marbles in the bag. b. Jordan adds 12 red marbles to the bag. Estimate the percent of marbles in teh bag that are red. show work 5- The name jalen is writeen on a piece of paper. The paper is then ripped into 5 pieces, with each piece having a letter on it. Answer the following question about prbability: a) P("A")= b) P(VOWEL)= C) P(NOT A VOWEL)= D)What percent of the time woud you expect to randomly choose the letter "L"? E)What percent of the time would you expect to randomly choose the letter "J" or"E"? 6- Leon uses the digits 5, 9, and 7 to creat as many 3-digit numbers. Each number is written on a piece of paper and puit into a hat. a. what's the probability of randomly selecting a nubme rthat begins with the digit 9? b. wht's percent of the time would you expect to choose a number that starts with eithe ra 5 or 9? 7- Mr. Rosenberg has a container of 80 pencils in his drawer. Half of the pencils are wooden. Out of the menchanical pencils, 20 are red, 10 are blue, adn 10 are green. a. If Mr. Rosenberg randomly takes a pencil out of the container, what is the probability that the pencil will be wooden? Explain how you got your answer. b. If Mr. Rosenberg randomly takes a pencil out of the container, what is teh probability that the pencil will be blue or green? Explain how you got your answer. Thank you so much for you help. I would really appreciate it. --------------------------------------------------------------

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