唔係幾明既數學題...

let x be the numbers of boys , let y be the numbers of girls
As the number of boys is 1/3(3份之1) more than that of girls.
so, x = (1+1/3)y
x = 4/3 y
as there are 42 students, so x+y = 42
4/3y + y = 42
7/3y = 42
y = 18
so x = 42 - y = 42 - 18 = 24

Ans: There are 24 boys and 18 girls in F.1A
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There are 42 students in F.1A.The number of boys is 1/3(3份之1) more than that of girls.Find the numbers ofboys and girls respectively.
我要let x be the numbers of boys , let y be the numbers of girls


let x be the numbers of boys , let y be the numbers of girls

The number of boys is 1/3(3份之1) more than that of girls, then
x = (1+1/3)y

x = (4/3)y, or

y = (3/4)x


The number of boys + that of girls = 42, then

x + y = 42, which can be written as

x + (3/4)x = 42

(7/4)x = 42

x = 42 * 4 ÷ 7

x = 24, and

y = (3/4)x

y = 24 * 3 ÷ 4

y = 18

Ans: There are 24 boys and 18 girls in F.1A respectively.