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.
