Correct Option: B
(A + B)’s 1 day’s work = | 1 | |
36 |
(B + C)’s 1 day’s work = | 1 | |
60 |
(C + A)’s 1 day’s work = | 1 | |
45 |
Adding all three,
2(A + B + C)’s 1 day’s work = | 1 | + | 1 | + | 1 |
36 | 60 | 45 |
2(A + B + C)’s 1 day’s work = | 5 + 3 +4 | = | 1 | |
180 | 15 |
∴ (A + B + C)’s 1 day’s work = | 1 | |
30 |
∴ C’s 1 day’s work = | 1 | - | 1 | |
30 | 36 |
C’s 1 day’s work = | 6 - 5 | | 1 | |
180 | 180 |
Hence, C alone will finish the work in 180 days.
Second method to solve this question ,Here , x = 36 , y = 60 , z = 45
C alone can do in = | 2xyz | |
xy - yz + zx |
C alone can do in = | 2 × 36 × 60 × 45 | |
36 × 60 - 60 × 45 + 45 × 36 |
C alone can do in = | 2 × 36 × 60 × 3 | |
144 - 180 + 108 |
C alone can do in = | 72 × 180 | = 180 days |
252 - 180 |