Let A represent the number that is increased by 50%
Let B represent the number that is decreed by 50%
A = 1 + (50/100)
A = 1.5
B = 1 - (50/100)
B = 0.5
(1.5A)*(0.5B) = 0.75AB.
0.75AB/AB
= 0.75 or 75%.
= 100% - 75% = 25% Decrease
Therefore, the product of two numbers if one of them is increased by 50%, and the other is decreased by 50% will decrease by 25%