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The ratio of number of boys to the number of girls in a school of 432 pupils is 5 : 4. When some new boys and girls are admitted, the number of boys increase by 12 and the ratio of the boys to girls changes to 7 : 6. The number of new girls admitted is
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- 12
- 14
- 24
- 20
Correct Option: C
| Original number of boys in school = | × 432 = 240 | |
| 9 |
Number of girls = 432 – 240 = 192
Let the new number of girls be x.
According to the question,
| = | ||
| 192 + x | 6 |
| ⇒ | = | ||
| 192 + x | 6 |
⇒ 192 × 7 + 7x = 252 × 6
⇒ 1344 + 7x = 1512
⇒ 7x = 1512 – 1344 = 168
| ⇒ x = | = 24 | |
| 7 |
