# Maths

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A moment ago, 80% of the children in a hall were girls. 48 girls and 2 boys left the hall. The remaining children were then told to form groups of 9. In each group, there were 2 boys. How many children were there in the hall first?

• Maths -

initially, b/g = 1/4
after some left, (b-2)/(g-48) = 2/7 since there were groups of 2 boys and 7 girls.

g=4b
7(b-2) = 2(4b-48)
b = 82
so g = 328

so, at first there were 410 children

after kids left, there were
80 boys
280 girls
making 40 groups of 2boys and 7girls

• Maths -

Dear Steve,

Thank you very much for your kind help.
Can understand clearly.

With regards,
Surya

• Maths -

Martha spent 4/a of her allowance on food and shopping.what fraction of her allowance had she
left

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