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If i assume all are girl and i can get the answer is 15.
But if i assume all are boy i cannot get the answer 15.
Where is my problem?
Please help
Date Posted: 6 years ago
Views: 571
Assume all 40 are boys.
Each boy gets 5 jellybeans.
So 40 x 5 = 200
Boys have 200 more as there are no girls.
Assume there is now 1 girl, 39 boys instead.
39 boys x 5 jellybeans each = 195 jellybeans
1 girl x 2 jellybeans each = 2 jellybeans
195 - 2 = 193
Comparing 200 to 193,
200 - 193 = 7
Notice that the difference between jellybeans of the boys and girls is reduced by 7 when you replace one boy with one girl.
From the question, we know boys only have 25 more than girls. We subtract 25 from 200.
200 - 25 = 175
175 ÷ 7 = 25
So it's as good as saying we replaced 25 of the boys with girls.
This means there are 25 girls actually.
Number of boys
= 40 - 25 = 15
Each boy gets 5 jellybeans.
So 40 x 5 = 200
Boys have 200 more as there are no girls.
Assume there is now 1 girl, 39 boys instead.
39 boys x 5 jellybeans each = 195 jellybeans
1 girl x 2 jellybeans each = 2 jellybeans
195 - 2 = 193
Comparing 200 to 193,
200 - 193 = 7
Notice that the difference between jellybeans of the boys and girls is reduced by 7 when you replace one boy with one girl.
From the question, we know boys only have 25 more than girls. We subtract 25 from 200.
200 - 25 = 175
175 ÷ 7 = 25
So it's as good as saying we replaced 25 of the boys with girls.
This means there are 25 girls actually.
Number of boys
= 40 - 25 = 15
See 2 Answers
done
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Using algebra to solve.
Date Posted:
6 years ago
done
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Alternatively, you can use the Guess and Check Method.
Date Posted:
6 years ago
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