The product of x and y is a constant. If the value of x is increased by 40%, by what percentage must the value of y be decreased?	Choose the most appropriate option: A) 34 % B) 36 % C) 28.57 % D) 30 % E) 32 %

Rationale: x * y = constt . let x = y = 100 in beginning i . e . x * y = 100 * 100 = 10000 x ( 100 ) - - - becomes - - - > 1.4 x ( 140 ) i . e . 140 * new ' y ' = 10000 i . e . new ' y ' = 10000 / 140 = 71.43 i . e . y decreases from 100 to 71.43 i . e . decrease of 28.57 % c
Answer: C