Question

90% of runners who started a marathon completed it. Of those, 30% are men. If 270 men completed the marathon, then how many total runners started the marathon?

Answer 1

Given- 90% of runner completed the marathon.

out of which 30% are man.

To proof - let the total number of runner be y.

the men completed the marathon be 30% of the 90%.

thus we have

30% of 90% of y = 270

`(30)/(100)`×
`(90)/(100)`×y = 270

now solving the above equation

we get

`\\y=(270* 100* 100)/(90* 30)`

Thus solving the equation

y = 1000

Thus the total runners of men who completed marathon be 1000.

Hence proved