A group of 120 Year 4s and Year 5s are going on a school trip. 60% of the children going on the trip are Year 4s, and of the Years 4s, 1/4 are boys. How many Year 4 girls are going on the trip?

There are quite a few stages to this problem, so let's work through each piece of information one by one.

We know that the total number of children is 120, and 60% are Year 4s. Finding 60% straight away can be tricky so we should find 10% first.

To find 10%, we just divide 120 by 10, which gives us 12. Now we know 12 = 10%, we need to multiply both numbers by 6 in order to find 60%. 

10% x 6 = 60%

12 x 6 = 72

So 72 students are in Year 4. 

We are told 1/4 are boys. So we need to find one quarter of the total number of students in Year 4. We do this by dividing 72 by 4. 

72 / 4 = 18

So we have 72 Year 4s, 18 of which are boys. However we want to find the girls. Therefore we take the total and subtract the number of boys:

72-18 = 54

There are 54 Year 4 girls on the trip