A alone can complete the project in 10 days; B alone can complete it in 20 days while C alone can complete it in 30 days. They together earn Rs.1,100 for the project. By how much do the total earnings of A and C exceed the earnings of B ?

Rs.500

A = 10 days, B = 20 days, C = 30 days,

⇒ Amount they receive working together = Rs. 1100.

⇒ (6 + 3 + 2)x = 1100

⇒ 11x = 1100

⇒ x = Rs. 100

⇒ The total earnings of A and C exceed the earnings of B by = (6 + 2 - 3) = 5 x 100 = Rs. 500