If A and B can together earn Rs. 540 in 6 days, B and C can together earn Rs. 420 in 5 days and A and C can together earn Rs. 644 in 7 days then in how many days can A, B and C working together earns Rs. 532?
If A and B can together earn Rs. 540 in 6 days, B and C can together earn Rs. 420 in 5 days and A and C can together earn Rs. 644 in 7 days then in how many days can A, B and C working together earns Rs. 532? Correct Answer 4
A and B can together earn Rs. 540 in 6 days
⇒ A and B ‘s 1 day earning = 540/6 = Rs. 90 ----(1)
B and C can together earn Rs. 420 in 5 days
⇒ B and C‘s 1 day earning = 420/5 = Rs. 84 ----(2)
A and C can together earn Rs. 644 in 7 days
⇒ A and C’s 1 day earning = 644/7 = Rs. 92 ----(3)
Let the required no. of days be n then A + B + C can earn 532/n in 1 day. ----(4)
From (1) and (4),
C’s 1 day earning = 532/n - 90
From (2) and (4),
A’s 1 day earning = 532/n - 84
⇒ A and C’s 1 day earning = 532/n - 90 + 532/n - 84 = 1064/n - 174 ----(5)
From (3) and (5),
1064/n - 174 = 92
⇒ n = 1064/266
⇒ n = 4