Rice is costlier than wheat by 25%.By what percent is wheat cheaper than rice.

Let cost of wheat be Rs. x.
Therefore, cost of rice will be Rs. x+(25%of x) = x+{(25/100)x}
=>Rs. x+{(1/4)x} = Rs. x+(x/4)
=> Rs. (x/1)+(x/4) = Rs. {(4x+x)}/4
=> Rs. 5x/4
Difference in the prices = Rs. [(5x/4)-x]
=> [(5x-4x)/4)] = x/4
Percentage = {(x/4)/(5x/4)}100
= {(x/4)(4/5x)}100
= (1/5)100
= 20
Therefore, wheat is 20% cheaper than rice.