• # question_answer In a school, the ratio of boys to girls is 4 : 5. When 100 girls leave the school, the ratio becomes 6 : 7. How many boys are there in the school? A)  1600   B)  1500C)  1300               D)  None of these

[d] Let number of boys = 4x Number of girls = 5x $\therefore$ $\frac{4x}{5x-100}=\frac{6}{7}$ $30x-600=28x$ $2x=600$ $x=300$ Number of boys $=4\times 300=1200$