Question:
In a school, the ratio of boys and girls is 4:5. When 100 girls leave the school, the ratio becomes 6:7. How many boys are there in the school?
A1800
B1200
C1000
D1500
Answer:
B. 1200
Explanation:
Let number of boys= 4x and number of girls= 5x According to the question 4x/(5x-100)=6/7 =>28x =6(5x-100) =>28x =30x-600 2x =600 x=600/2=300 Number of boys= 4x=4x300=1200