Toán Lớp 5: The ratio of the number of girls to the number of boys in a classrom was 5:4.When 10 girls left the classrom, the ratio of the number of boys to the number of girls became 4:3. How many students were there in the classrom at first?
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Ratio of boys and girls=2:3
2+3=5
No. of boys =52×100=40
No. of girls=53×100=60
If 20% of the boys leaves the class then 20% of 40
10020×40=8
Now number of boys=40−8=32
New ratio=32:60⇒8:15
Ratio of boys and girls=2:3
2+3=5
No. of boys =52×100=40
No. of girls=53×100=60
If 20% of the boys leaves the class then 20% of 40
10020×40=8
Now number of boys=40−8=32
New ratio=32:60⇒8:15