About 3.8 hours, if asking for a whole number round to 4
Answer:
C
Step-by-step explanation:
m = -3
y = mx +b
y = -3x + b
Plugin x = -1 and y = 4
4 = -3*(-1) +b
4 = 3 + b
4-3 = b
b = 1
y = -3x + 1
In 15 days he would have downloaded 45 songs. In 40 days he would have downloaded 120 songs.
500 at 40 each = £20000
To make a profit he needs to make more than £20000
20 broke so he sold 500-20 = 480 at 45 each.
480 x 45 = 21600
Profit = 21600 -20000 = 1600
His profit was £1,600
