A is as efficient as B and C together. Working together A and B can complete a work in 36 days and C alone can complete it in 60 days. A and C work together for 10 days. B alone will complete the remaining work in:

Let the total work be 180 units.
($$\because$$ LCM of 36 and 60 is 180.)
Efficiency of A + B = 180/36 = 5 ---(1)
Efficiency of C = 1890/60 = 3
Efficiency of A = Efficiency of (B + C)
Efficiency of A - B = Efficiency of C
Efficiency of A - B = 3 ---(2)
From eq (1) and (2),
2A = 8
Efficiency of A = 4
Efficiency of B = 5 - 4 = 1
Work done by (A + C) in 10 days = (4 + 3) $$\times$$ 10 = 70 units
Remaining work = 180 - 70 = 110 units
Time taken by B to complete the remaining work = 110/1 = 110 days