20. READING: The number of pages P a student can read varies directly with the amount of time T in minutes spent reading. The student can read 90 pages in 60 minutes. Write an equation that relates P and T. PREDICT the number of pages the student can read if 90 minutes is spent reading.
21. MOVIES: The Cost C of going to the movies varies directly with the number N of people attending. A group of four paid $14 to go to the movies on Friday. Write an equation that relates C and N. How much would it cost for 7 people to go to the movies?
CAN SOMEONE HELP ME PLEASE? STRUGGLING WITH BOTH OF THESE ?'s... PLEASE HELP!!! Merci.
P = k T
90 = k (60)
k = 9/6 = 1.5 pages/min
if T = 90
P = 1.5*90 = 135
=====================
C = k N
14 = k (4)
k = 14/4 = 7/2
so
C = 3.5 N
if n = 7
C = 3.5 * 7 = 49/2 = 24.5
I got something different but I'll figure out how you got that. Thankyou.
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20. To write an equation that relates the number of pages read (P) with the amount of time spent reading (T), we can use the concept of direct variation. In this case, we are told that the number of pages read varies directly with the amount of time spent reading.
We are given that the student can read 90 pages in 60 minutes. Let's call this the "constant of variation." The constant of variation represents the ratio between the variables P and T.
To find the constant of variation, we divide the number of pages (P) by the amount of time (T):
90 pages / 60 minutes = 3/2 pages per minute
So, the constant of variation is 3/2, which means that the student can read 3/2 pages per minute.
Now, we can write the equation relating P and T:
P = (3/2)T
To predict the number of pages the student can read if 90 minutes is spent reading, we substitute T = 90 into the equation:
P = (3/2)(90) = 135
Therefore, the student can predictably read 135 pages if 90 minutes is spent reading.
21. To write an equation that relates the cost of going to the movies (C) with the number of people attending (N), we can use the concept of direct variation. In this case, we are told that the cost varies directly with the number of people attending.
We are given that a group of four people paid $14 to go to the movies. Let's call this the "constant of variation." The constant of variation represents the ratio between the variables C and N.
To find the constant of variation, we divide the cost (C) by the number of people (N):
$14 / 4 people = $3.50 per person
So, the constant of variation is $3.50, which means that the cost is $3.50 per person.
Now, we can write the equation relating C and N:
C = $3.50N
To find out how much it would cost for 7 people to go to the movies, we substitute N = 7 into the equation:
C = $3.50(7) = $24.50
Therefore, it would cost $24.50 for 7 people to go to the movies.