Answer:
<u>5.56 hours</u>
Step-by-step explanation:
Margo read 42 pages in 2.5 hours.
Pete read six fewer pages in the same amount of time.
So, The number of pages that Pete reads = 42 - 6 = 36 pages
So, Pete read 36 pages in 2.5 hours.
let the time needed to read 80 pages x
∴ 36 pages ⇒ 2.5 hours
80 pages ⇒ x hours
∴
Using cross multiplication:
∴
So, The time taken to read 80 pages
= <u>5.56 hours = 5 hours and 33.33 minutes</u>
Answer:
7
Step-by-step explanation:
4 and 1/2 + 6 and 7/8 = 11 and 3/8 cups
(11 and 3/8) / (1 and 5/8) = 7 scoops
Optimum is reached when the derivate equals zero
derivate of C is 2*0.045x-220 which is 0.09x-220
0.09x-220=0
x=220/0.09
x=2444,44 say 2445 units.