Please answer the following question by reasoning step-by-step.
Frank spent 1/5 of his money to buy groceries. He then spent 1/4 of the remaining money to buy a magazine. If he had $360 left in his wallet, how much money did he have at first?

600
Let X be the money Frank had originally.

Frank spent 1 / 5 * X on groceries.

Frank spent 1 / 4 * (X - 1 / 5 * X) on a magazine.

Frank has X - 1 / 5 * X - 1 / 4 * (X - 1 / 5 * X) = $360 left in his wallet.

Multiplying through the parentheses, we get X - 1 / 5 * X - 1 / 4 * X + 1 / 20 * X = $360.

Combining like terms, we get 12 / 20 * X = $360.

Dividing both sides by 12 / 20, we get X = $600.

.

Thus, the answer is 600