Question

In a marathon, 90% of runners managed to complete it and 30% of them were men. If 270 men completed it, how many total runners began the marathon?

Answer 1

Let the no. of runners be x.

If 90% of runners complete it, then no. of runners,

`{\sf{ (90)/(100) * x = (9x)/(10)}}`

If 30% of completed runners are men, then no. of men,

`{\sf{\frac{30} {100} * (9x)/(10) = (27x)/(100)}}`

According to given,

`{\sf{(27x)/(100) = 270 \\ →x = 270 * (100)/(27) \\ →x = 1000}}`

Hence, 1000 runners started the marathon.