# When a runner was crossing the 12 km mark

Percentages
When a runner was crossing the 12 km mark, she was informed that she had completed only 80% of the race. How many kilometres was the runner supposed to run in this event?

- 14
- 15
- 16
- 16.5

### Answer

Let the total length of event be x km.

80% of x = 12

80x/100 = 12

80x = 1200

x = 15

**The correct option is B.**