HiJcong wrote:The number of the marbles in Box A, Box B and Box C was 195. John added 60 marbles to those in Box A, doubled the number of marbles in Box B and halved the number of marbles in Box C. The ratio of the number of marbles become 4:1:2. What is the total number of marbles in the three boxes now?

In the end, the ratio of marbles in box A, B, C -

A : B : C

= 4 : 1 : 2

= 8u : 2u : 4u >> total 14u

Initially,

A : B : C

= 8u - 60 : u : 8u

So, 8u - 60 + u + 8u = 195

17u = 255

1u = 15

14u = 14 x 15 = 210

There are 210 marbles in all the boxes now.

cheers.