Solution for Question 1

Question 1

88 children took part in a swimming competition. 1/3 of the boys and 3/7 of the girls wore swimming goggles. Altogether, 34 children wore swimming goggles. How many girls wore swimming goggles on that day?
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Solution 

Let b = the number of boys in total that competed in the swimming competition

Let g = the number of girls in total that competed in the swimming competition

b + g = 88 ---> Equation number 1
1/3 b + 3/7 g = 34 ---> Equation number 2

Multiply equation 2 by 3 to get a 'whole number' of boys

b + 9/7 g = 102 ---> Equation number 3

Minus Equation number 1 from equation number 3

2/7 g = 102-88 = 14

The total number of girls = 49

The question asks for the girls that wore swimming goggles - 3/7 of this.

3/7 x 49 = 21

Therefore, 21 girls wore swimming goggles on the day.

(I don't know if Grade 5/6 students will be able to follow this though... but ^^")