Question

15:13, find the ratio p:9:1
23. The ratio of boys in three classes is 4: 5: 7.
If the boys in first class are doubled and
those in the second class are halved, find
the new ratio of the boys in the three
classes.
(A) 16:5:14 (B) 8:5:14
(C) 8:10:14 (D) 4:10:14​

Answer 1

Answer:

Let the actual number of boys in the classes be 4x, 5x and 7x.

The new numbers on doubling the number in first class and halving the number in the second class: (2 × 4x), (5x/2) and 7x.

=> 8x : 5x/2 : 7x

=> 16x : 5x :14x ______(On multiplying by 2)

=> 16 : 5 : 14 ________(On dividing by x)

${\huge{\underline{\underline{\red{\sf{Answer:- (C) 16 : 5 : 14}}}}}}$