Question

Serena asked her parents if for their picnic they could have 20% more portions of coca-cola than they planned, and if each portion could be 20% bigger. Her parents agreed. By what percent more coca cola will they buy?

Answer 1

Answer:

44%

Step-by-step explanation:

If p represents the number of portions and q represents the quantity in each portion, then the original amount needed was p·q.

After p is increased by 20%, its number is ...

p + 0.20·p = 1.20·p

After q is increased by 20%, its amount is ...

q + 0.20 ·q = 1.20·q

Then the new amount the parents must buy is ...

(1.20p)(1.20q) = 1.20²·pq = 1.44pq

This amount is ...

(1 + 44/100)·pq = pq + 44%·pq

It is 44% more than the original planned purchase.