Question

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?

(a) 14

(b) 15

(c) 16

(d) 16.5

Answer 1

Correct option is (b) 15

Let the runner suppose to run n km.

then, n x \(\frac{80}{100}\) = 12

⇒ n = \(\frac{12 \times100}{80}\) = 15 km.

Answer 2

(b) 15

0.80 x (race length) = 12 km

race length = 12 km / 0.80 = 15 km