If Lwandi got her test back and was very happy because she got 85%. To get full marks she needed to get 60 marks. How many marks did she lose?

0.15 * 60 = ?

To find out how many marks Lwandi lost, we need to subtract the score she got (85%) from the perfect score (100%).

Step 1: Convert the percentage to a decimal. Divide the percentage by 100.
85% ÷ 100 = 0.85

Step 2: Subtract the decimal score from 1 (since 1 represents a perfect score).
1 - 0.85 = 0.15

Step 3: Multiply the result by the number of marks required for full marks.
0.15 × 60 = 9

Therefore, Lwandi lost 9 marks.