Question

There are 39 people on a city bus. The ratio of adults to children is 10 : 3. At the next stop, 3 adults get off the bus. What is the new ratio of adults to children on the bus?

A 3 : 1

B 9 : 2

C 7 : 3

D 12 : 1​

Answer 1

3:1

Explanation:

Looking at the numbers

39 and a ratio of 10:3 kinda scream that there are 30 adults and 9 children to me, but when 3 adults get off, that is only 36 people.

this means,

27 adults,

and

9 children

so if it doesn't look obvious enough, 9 x 3 is 27, so that means that 3: 1 must be our ratio because the 3 in 3:1 multiplied by 9 is 27 which is the number of adults, and the 1 in children multiplied by 9 is 9!

so there you have it, 27/9 = 3

and

9/9=1

so

3: 1