Question
In a store, a box of files costs thrice as much as a manual. Mrs Ma spent 15 of her money to buy 6 boxes of files. She then spent 79 of her remaining money to buy some manuals and had $20.80 left. How much does each manual cost?
4 m

Click button first when a symbol is required. X

In a store, a box of files costs thrice as much as a manual. Mrs Ma spent 15 of her money to buy 6 boxes of files. She then spent 79 of her remaining money to buy some manuals and had $20.80 left. How much does each manual cost?