In a school, there are 550 students. The ratio of the boys to that of the girls is 6 : 5. How many more girls should join the school so that the ratio becomes 5 : 6?
Answer & explanation
Correct answer: option 4
Boys : Girls
6 : 5
⇒ (6 + 5) units = 550
⇒ 11 units = 550
⇒ 1 unit = 50
⇒ No. of boys = 6 x 50 = 300
⇒ No. of Girls = 5 x 50 = 250.
⇒ No. of girls that should join the school so that the ratio becomes 5 : 6
⇒ 5 units = 300
⇒ 1 unit = 60,
⇒ Therefore, 6 units = 6 x60 = 360
⇒ No. of Extra girls joined = 360 - 250 = 110.