There is 3x = 3.5y = 4z—(1).

X+y+z = 3650-(2)

Solve the formula (1)(2) to get x= 1400, y= 1200 and z= 1050.

A: .......

Or, scheme 2: let the same time be t.

Then t/3+t/3.5+t/4=3650.

T=466+2/3 (minutes)

So A made 3*(466+2/3)= 1400. Similarly, B and C made 1200 and 1050.