Question

There are a total of 96 children in Years 4, 5 and 6

37 of these children cannot swim.
11 children in Year 4 cannot swim.
21 children in Year 5 can swim.
There are 30 children in Year 6
18 of these 30 children can swim.
(i) Work out the number of children in Year 4 who can swim.

Answer 1

Answer: 20 children

Explanation:

Given

Year 4: 11 cannot swim

Year 5: 21 can swim

Year 6: 18 of 30 can swim

Total 96 children

Total 37 cannot swim

First Step: find the number of people from year 5 who cannot swim

• There are 30-18=12 people who cannot swim in year 6
• There are 11 who cannot swim in year 4
• Thus, we use the total number [37]-[year 4+year 6]=37-23=14 people who cannot swim in the year 5

Second Step: find the number of children in year 5

• There are 21 children who can swim
• There are 14 children who cannot swim
• 21+14=35 children

Third Step: find the number of children in year 4 who can swim

• There are 30 children in year 6
• There are 35 children in year 5
• There are 11 children in year 4 who cannot swim
• There are in total 96 children
• 96-30-35-11=20 children in year 4 who can swim

Hope this helps!! :)

Please let me know if you have any questions