Question

Jagdish can build a wall in 10 days. narender can build the same wall in 12 days while sumit takes 15 days to do the same job. which two of them should be employed to finish the job in 6 days?

a. jagdish and narender

b. jagdish and sumit

c. sumit and narender

d. none of the above

Answer 1

c....NARENDER AND SUMIT

Answer 2

Solution:

Time taken by Jagdish to build the wall = 10 days

Jagdish one day's work = $\frac{1}{10}$

Time taken by Sumit to build the wall = 15 days

Sumit one day's work = $\frac{1}{15}$

Time taken by narender to build the wall = 12 days

Narender one day's work = $\frac{1}{12}$ days

(Jagdish + Narender) 1 day's work = $\frac{1}{10} +\frac{1}{12} = \frac{11}{60}$

(Jagdish+sumit ) 1 day's work = $\frac{1}{10}+ \frac{1}{15} =\frac{15 + 10 }{150}=\frac{25 }{150}=\frac{1}{6}$

(Sumit + Narender ) 1 day's work = $\frac{1}{12}+ \frac{1}{15} =\frac{5+4}{60}=\frac{9}{60}=\frac{3}{20}$

→ So, jagdish and sumit can complete the assigned work in 6 days.

→ Option b is true.