Question 2: G who can complete whole work in 30 days replaced A and did A’s part of work. He left and then B also worked for same number of days as G. If remaining work was completed by M who can do complete work in one-fourth the number of days in which E can complete the work, then in how many days was the whole work completed?

A.22 days         B.14 days         C.21 days         D.18 days         E.12 days

Solution:

A’s part of work = 20% =1/5

So, G did 1/5 of work and whole work in 30 days,1/5

=> 1/5 work in 1/5 x 30=6 days

Now, B also worked for 6 days.

B can complete 10% of work in 3 days.
So, B can complete the whole work in taken time =100 x 3/10=30days
So, in 6 days,

B completed 6/30= 1/5 of work

Now, remaining work

Now, E can complete 15% of work in 6 days. 
So, E can complete the whole work in taken time

=100 x 6/15=40 days

M can complete the work in 1/4th of No. of days of E.

=1/4 x 40= 10 days.

So, M completed 3/5 work in taken time 

3/5 x 10=6 days
Hence, total number of days
=   6 + 6 + 6
=   18
Therefore, option D is correct.

Question 3: If all people divides the work equally. In how many days will the work be completed this way?

A.20 days         B.36.8 days      C.38 days         D.26.8 days      E.None of these

Solution:

People equally divided the work so each did 1/5 work now 

A does 1/5^th work in 8 days 
B does 1/10th (10%) work in 3 days
⇒   1/5^th of work in 6 days 

C does 1/4^th (25%) work in 6 days
⇒   1/5^th work in 4.8 days

D does 3/10^th (30%) work in 15 days
⇒   1/5^th work in 10 days 

E does 3/20^th (15%) work in 6 days
⇒   1/5^th work in 8 days 

Hence, total work completed in
=   8 + 4.8 + 6 + 10 + 8
=   36.8 days

Therefore, option B is correct.

Question 4: P is 20% more efficient than B and Q is 60% more efficient than C. They worked together for 5 days and left the work, after which the remaining work was completed by D in ?

A.23 days         B.15 days           C. 23(1/3) days          D. 26(1/3) days      E. None of these

Solution:

B can complete 10% of work in 3 days.
So, B can complete the whole work in 100 x 3/10= 30 days

As P is 20% more efficient than B

⇒ P can complete the work in 25 days

C can complete 25% of work in 6 days.
So, C can complete the whole work in 100 x 6/25= 24 days

As Q is 60% more efficient than B

⇒ Q can complete the work in 15 days

Now, P & Q worked for 5 days,

=> 5/25 + 5/15  = 8/15

Remaining Work= 7/15

D can complete 30% of work in 15 days.
So, D can complete the whole work in 100 x 15/30 = 50 days
So, D does 7/15th of work in 50 x 7/15= 23(1/3) days

Hence, option C is correct.