Question

Please help, At a festival 2/7th of the number of girls was equal to 3/5th of the number of boys.

Answer 1

Answer:

465

Step-by-step explanation:

Let the number of girls at the festival be--------- g

Let the number of boys at the festival be---------b

The conditions are;

2/7 g = 3/5 b ---------------(i)

g-b= 165 ---------------------(ii)---------make g the subject of the expression

g= 165 +b---------------------(iii)--------use this equation in (i)

2/7 (165 +b)= 3/5 b -------multiply both sides by 7

7*2/7(165+b) =3/5*7 b

2(165+b)=21/5 b ------multiply both sides by 5

5*2(165+b) = 21/5*5*b

10(165+b) = 21 b -------open brackets

1650 +10 b = 21 b------collect like terms

1650 = 21 b- 10 b

1650 = 11 b -----divide both sides by 11

1650/11 = 11b/11

150 = b = number of boys

Using equation (ii) where g-b =165  ;  g-150 =165 , g= 165+150 =315 number of girls

Total number of children at the festival = 150+315 =465