You may want to elaborate on what you mean by "square root problems"
2 peach pies = 10 cups 10 divided by 2(peach pies) = 5 cups per pie.
so we need to make 9 pies. so now basic math 9x5= 45, so 45 cups for 9 peach pies.
You are basically asking 160% of X = 70.
1) 70 x 100 = 7000 (to turn the 70 into a %)
2) 7000 /160 = 43.75
You can reverse the equation to double check the answer.
160% x 43.75 = 70