If w is 10 percent less than x, and y is 30 percent less than z, then wy is what percent less than xz?

Correct Answer: 37%
w is 10% less than x i.e 90% of x = . 90x similarly y = . 70z wy = . 90x ×. 70z = . 63xz ( 100 - 63) = 37% less