Question

10 workers can finish the job in 15 days. For the first 5 days, only 6 workers worked on the job. Then for the next 3 days 2 more workers joined them. To finish the job, 4 more workers joined them. After how many days was the whole job done?
a) 8 days
b) 12 days
c) 16 days
d) 18 days ​

Answer 1

Answer:

Given :- 10 workers can finish the job in 15 days. For the first 5 days, only 6 workers worked on the job. Then for the next 3 days 2 more workers joined them. To finish the job, 4 more workers joined them. After how many days was the whole job done ?

Answer :-

Let efficiency of each worker is 1 unit / day .

so,

→ Total work = 10 * 1 * 15 = 150 units .

now,

→ for first 5 days , 6 worker completes = 5 * 6 * 1 = 30 units .

and,

→ for next 3 days, 8 workers completes = 3 * 8 * 1 = 24 units .

now, 4 more workers joined .

so,

→ Total workers are = 12 workers .

and,

→ left work = 150 - 30 - 24 = 96 units .

therefore,

→ Time taken by 12 workers to complete remaining work = 96/12 = 8 days .

hence,

→ Whole job was done in = 5 + 3 + 12 = 20 days (Ans.)

Step-by-step explanation: