Question

By what percent will the product of two numbers decrease if one of them is decreased by 20% and the other is decreased by 60%?

Answer 1

68

Explanation:

RSM again

Answer 2

We have:

P1 = a x b

If a decreases by 20% and b decreases by 60%, then we have:

P2 = a x (100 - 20)/100 x b x (100 - 60)/100

= a x 80/100 x b x 40/100

= a x b x 8/25

=> P1 - P2 = ab - (8/25)ab = (17/25)ab

=> If a decreases by 20% and b decreases by 60%, product of a and b would decrease 17/25 = 0.68%

Hope this helps!

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