Question

There are 600 people on a cruise ship.

The over 30s and the 30 and unders are in the ratio 4:1.
30% of the over 30s are female.
Work out how many of the over 30s are male.
Submit Answer
males over 30

Answer 1

Explanation:

600 people is the total number of people.

with a given ratio of 4:1 we know that this total number of people is basically split into 5 (4 + 1) equal units.

each of the 5 units is therefore

600 / 5 = 120 people.

the "over 30s" are 4 of these units = 4 × 120 = 480 people.

the "30 and under" are 1 unit = 120 people.

30% of these 480 "over 30" people are female.

that leaves under normal circumstances 100 - 30 = 70% of these 480 "over 30" people to be male.

100% = 480

1% = 100%/100 = 480/100 = 4.8

70% = 1% × 70 = 4.8×70 = 48×7 = 336 people.

there are 336 males over 30 on that ship.