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40% of the children at a childcare centre are boys. If there are 18 more

girls than boys, how many children are there?

40% of the children at a childcare centre are boys. If there are 18 more girls than-example-1
User Markych
by
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2 Answers

4 votes

Answer:

i think 90

Explanation:

No of boys = 40%

let total no. of children be as "x"

now, 40% of x= 2x/5.

and since boys differ girls by 18.

no. of girl would be x-2x/5=3x/5.

now No. of boys= 2x/5

and no. of girls= 3x/5

no. of total children would then be as = 3x/5 - 2x/5= 18

The value of "X" would then be as = 90

To find no. of boys we would do 2x/5 X 90= 36

and no. of girls = 3x/5 X 90= 54.

to prove my answer 54-36= 18

Hope it helps C":

User Khkarens
by
5.7k points
4 votes

Suppose there are X children at the childcare.

Thus :

boys + girls = X

__________________________

40% of the children are boys .

Thus :

There are 40/100 × X boys .

So : boys = 0.4X (( Ω ))

__________________________

There are 18 more girls than boys

Thus :

girls - boys = 18

girls - ( 40/100 X ) = 18

girls - 0.4X = 18

Add sides 0.4X

girls - 0.4X + 0.4X = 18 + 0.4X

girls = 18 + 0.4X (( μ ))

__________________________

Now It's time to put (( μ ))

and (( Ω )) in the above equation.

boys + girls = X

0.4X + 18 + 0.4X = X

0.8X + 18 = X

Subtract sides 0.8X

- 0.8X + 0.8X + 18 = 1X - 0.8X

18 = 0.2X

0.2X = 18

Divided sides by 0.2 (( 2/10 ))

2/10 ÷ 2/10 × X = 18 ÷ 2/10

X = 18 × 10/2

X = 18 × 5

X = 90

Thus there are 90 children at the childcare.

Done.....♥️♥️♥️♥️♥️

User Davagaz
by
5.6k points