40% of a is b and b% of 40 is c% of a. What is c?

Let's break down the problem step by step:

1. "40% of a is b": This means that 40% of the value of a is equal to b. Mathematically, we can express this as: 0.4a = b.

2. "b% of 40 is c% of a": This means that b% of the value 40 is equal to c% of the value of a. Mathematically, we can express this as: (b/100) * 40 = (c/100) * a.

Now, we can solve for c by substituting the value of b from the first equation into the second equation:

(b/100) * 40 = (c/100) * a (0.4a/100) * 40 = (c/100) * a 0.4 * 40 = c 16 = c

Therefore, c is equal to 16.