If each side of a square is decreased by 17%, then by what percentage does its area decrease?

31.11%

17% = \(\frac{17}{100}\)

Side             100        :        83

--------------------------------------------

Area         10000        :      6889

{ Area = Side × Side }

Decreased percentage = \(\frac{10000 - 6889}{10000 }\) × 100

= \(\frac{3111}{10000 }\) × 100 = 31.11%