可汗学院
31.p=100h-2000
It costs $2,000 a month for Mia to rent space to run her law firm. She charges $100 per hour for legal advice. The equation above gives Mia’s profit, P, per month, after working h hour. How many hours does Mia have to work before she starts to make money each month?
A.20 hours
B.80hoursO
C.100hours
D.200hours
Correct answer: A Difficulty level: 3
32.C=1.5b+67.5
The total cost, C, in dollars, to produce b books is given by the equation below. What is the meaning of 1.5 in the equation?
A.1.5 books will cost $67.50 to produce.
B.It costs an extra $1.50 for each book produced.
C.If you produce one book, you total cost will be $1.50
D.There is a flat fee of $1.50 to produce any number of books.
Correct answer: B Difficulty level: 4
33.B=0.55A
Jing is making homemade peanut butter. The equation above shows the amount of peanut butter yielded, B, in cups, for A cups of peanuts. What percentage of the volume of peanuts is lost when processing them into peanut butter?
A.0.55%
B.0.45%
C.55%
D.45%
Correct answer: D Difficulty level: 4
34.P=0.7c
A store is having a sale on every item purchased. Irina decides to take advantage of the sale and purchases a sweater. The equation that gives the after-sale price, P, of Irina’s sweater with an original cost, c, is shown above. What percent off the original cost did Original cost did Irina save?
A.3%
B.7%
C.30%
D.70%
Correct answer: C Difficulty level: 4
35.T=1200-0.06c
A print shop copies and prints documents in large volume for its customers. For a particular copy machine, the equation above gives the amount of toner, T, in grams, left after making c copies.
How many grams of toner are used per copy?
Correct answer: 0.06 Difficulty level: 4