EduGoog

Time & Work

21 labourers can build a wall in 25 days. If 14 additional labourers are employed, then in how many days the work can be completed ?

Option:
A. 19 days
B. 12 days
C. 14 days
D. 15 days
Answer: D . 15 days

Justification:

Original labourers = 21
Additional labourers = 14
Total labourers = 21 + 14 = 35.
21 labourers can build a wall in = 25 days.
1 labourers can build a wall in = 25 x 21 days.
35 labourers can build a wall in = ${25 × 21}/35$ = 15 days

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