To answer this question, all you really have to do is reword the problem to make it: 140% of n=56. In math, the word of means multiply. So it's 140%*n=56. The reverse operation of multiply is to divide. 56/140%=n. 140% can also be written as 1.4, so 56/1.4=n. Use any algorithm you'd like and solve. Your answer is 40!