Three sisters have a total of $91. The first sister has 20% more than the second and the second sister has 20% more than the third. How much does the first sister have?

When faced with a puzzle involving relative amounts, a clever strategy is to start with the unknown quantity that other values are compared against. In this scenario, the third sister's share is the perfect starting point. If we denote her amount as 'X', we can then build the other sisters' shares from this base, untangling the relationships one step at a time.

The second sister has 20% more than the third, which means her share is X plus an additional 20% of X, or simply 1.2 times X. Following this logic, the first sister has 20% more than the second. Her share is therefore 1.2 times the second sister's amount. Since the second sister's share is 1.2X, the first sister's share becomes 1.2 multiplied by (1.2X), resulting in 1.44X.

With all three shares now expressed in terms of X – X for the third, 1.2X for the second, and