1. The problem statement, all variables and given/known data a and B are two variables such that their product ab = constant .If a increases by 10%, by how much does b decrease ? 2. Relevant equations 3. The attempt at a solution ab = constant If a changes to 11a/10 , then b has to change to 10b/11. % Change in b is = (b - 10b/11)/b = 9.09% b decreases by 9.09% . But the answer given is 10% . Is 9.09% decrease in b correct ?