# Time and Work Quiz Set 005

### Question 1

A can finish a work in 15 days. B can do the same work in 11 days. They work together for 4 days. The fraction of work that is left is?

A

\${61/165}\$.

B

\$1{61/165}\$.

C

\${61/164}\$.

D

\${31/83}\$.

Soln.
Ans: a

They together finish \$1/15 + 1/11\$ work in a day. In 4 days they finish 4 × \$(1/15 + 1/11)\$ work, which is \$104/165\$. So the un-finished work is 1 - \$104/165\$ = \${61/165}\$.

### Question 2

A, B and C can independently complete a work in 17, 18 and 19 days respectively. B and C start the work together, but A joins them after 3 days. In how many days will the work be completed?

A

\$7{43/971}\$ days.

B

\$8{43/971}\$ days.

C

\$9{43/971}\$ days.

D

\$10{43/971}\$ days.

Soln.
Ans: a

Use the shortcut formula. If A, B, C can independently complete the job in x, y and z days, and A joins after n days, the work is completed in \${xyz}/{xy + yz + zx}\$ × \$(1 + n/x)\$ days. Putting the various values x = 17, y = 18, z = 19, n = 3, and simplifying, we get \${6840/971}\$, which is same as: \$7{43/971}\$.

### Question 3

A can do a piece of work in 46 days. B is 15% more efficient than A. In how many days can B complete that work?

A

20 days.

B

21 days.

C

19 days.

D

22 days.

Soln.
Ans: a

Let us first calculate the one day work of B. One day work of A is given as \$1/46\$. If B is 15% efficient, then one day work of B is \$1/46\$ × \$115/100\$ = \$1/20\$. Which gives 20 days as the answer.

### Question 4

A can do a piece of work in 46 days. B is 15% more efficient than A. In how many days will they complete the work if they work together?

A

\$13{31/33}\$ days.

B

\$13{32/33}\$ days.

C

14 days.

D

\$14{1/33}\$ days.

Soln.
Ans: a

Let us first calculate the one day work of B. One day work of A is given as \$1/46\$. If B is 15% efficient, then one day work of B is \$1/46\$ × \$115/100\$ = \$1/20\$. Putting x = 46 and y = 20 in the shortcut method, we get \${xy}/{x + y}\$ = \${460/33}\$, which is same as: \$13{31/33}\$.

### Question 5

A can harvest a field in 11 days. B can do the same work in 14 days. In how many days will they together harvest the field?

A

\$6{4/25}\$ days.

B

\$7{4/25}\$ days.

C

\$8{4/25}\$ days.

D

\$9{4/25}\$ days.

Soln.
Ans: a

Putting x = 11 and y = 14 in the shortcut method, we get \${xy}/{x + y}\$ = \${154/25}\$, which is same as: \$6{4/25}\$.

Updated on 2017-05-17.

Posted by Parveen(Hoven),
Aptitude Trainer