Question

Please help me with this problem in the picture.

Answer 1

Let the number of girls be x.

Number of boys =
`(3)/(5)x`

Number of children = 120


`x + (3)/(5)x = 120`


`(5x + 3x)/(5) = 120`


`8x = 600`


`x = (600)/(8) = (300)/(4) = (150)/(2) = 75`

Hence, the number of boys are
`(3)/(5)*75 = 3*15 = 45` boys.

Answer 2

b + g = 120
b = 3/5g

3/5g + 5/5g = 120
8/5g = 120
g = 120 / (8/5)
g = 120 * 5/8
g = 600/8 = 75 <== 75 girls

b = 3/5g
b = 3/5(75)
b = 225/5 = 45 <=== 45 boys