Question

When 5 children from class A join class B, the number of children in both classes is the same. If 25 children from B, join A, then the number of children in A becomes double the number of children in B. The ratio of the number of children in A to those in B is:

• A. 9 : 8
• B. 19 : 18
• C. 19 : 17
• D. 18 : 17

Answer 1

Answer:

C. 19 : 17

number of children in class A= a number of children in class B = b 5 children from class A join class B a - 5 = b + 5 a - b = 10 -----(1) when 25 children from B join A, the number of children in A becomes double the number of children in B a + 25 = 2 × (b - 25) 2b - a = 75 -----(2) b = 85 a= 95