Mathematics
NULL
Medium
Question
A and B finish a work in 20 days, B and C in 30 days, C and A in 40 days. In how many days can A alone finish it?
A
48
✓ Official correct answer
B
34(2/7)
C
44
D
45
Community credibility
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A
48
No member explanations yet for this option.
B
34(2/7)
No member explanations yet for this option.
C
44
No member explanations yet for this option.
D
45
No member explanations yet for this option.
Explanation
A+B+C = (1/20 + 1/30 + 1/40)/2 = 13/240. Then A = 13/240 − 1/30 = 1/48 ⇒ 48 days.