Author name: Admin

✅ The correct answer is option A.
P can complete the work in (12 x 8) hrs. = 96 hrs.
Q can complete the work in (8 x 10) hrs. = 80 hrs.

P’s1 hour’s work =
1
and Q’s 1 hour’s work =
1
.

96
80

(P + Q)’s 1 hour’s work =

1
+
1

=
11
.

96
80
480

So, both P and Q will finish the work in

480

hrs.

11

Number of days of 8 hours each =

480
x
1

=
60
days = 5
5
days.

11
8
11
11

✅ The correct answer is option B.
Suppose A, B and C take x,
x
and
x
days respectively to finish the work.

2
3

Then,

1
+
2
+
3

=
1

x
x
x
2

6
=
1

x
2

x = 12.
So, B takes (12/2) = 6 days to finish the work.

✅ The correct answer is option D.
(A + B)’s 20 day’s work =

1
x 20

=
2
.

30
3

Remaining work =

1 –
2

=
1
.

3
3

Now,
1
work is done by A in 20 days.

3

Therefore, the whole work will be done by A in (20 x 3) = 60 days.

✅ The correct answer is option A.
Work done by X in 8 days =

1
x 8

=
1
.

40
5

Remaining work =

1 –
1

=
4
.

5
5

Now,
4
work is done by Y in 16 days.

5

Whole work will be done by Y in

16 x
5

= 20 days.

4

X’s 1 day’s work =
1
, Y’s 1 day’s work =
1
.

40
20

(X + Y)’s 1 day’s work =

1
+
1

=
3
.

40
20
40

Hence, X and Y will together complete the work in

40

= 13
1
days.

3
3

✅ The correct answer is option C.
A’s 1 hour’s work =
1
;

4

(B + C)’s 1 hour’s work =
1
;

3

(A + C)’s 1 hour’s work =
1
.

2

(A + B + C)’s 1 hour’s work =

1
+
1

=
7
.

4
3
12

B’s 1 hour’s work =

7
–
1

=
1
.

12
2
12

B alone will take 12 hours to do the work.

✅ The correct answer is option A.
2(A + B + C)’s 1 day’s work =

1
+
1
+
1

=
15
=
1
.

30
24
20
120
8

Therefore, (A + B + C)’s 1 day’s work =
1
=
1
.

2 x 8
16

Work done by A, B, C in 10 days =
10
=
5
.

16
8

Remaining work =

1 –
5

=
3
.

8
8

A’s 1 day’s work =

1
–
1

=
1
.

16
24
48

Now,
1
work is done by A in 1 day.

48

So,
3
work will be done by A in

48 x
3

= 18 days.

8
8

✅ The correct answer is option C.
Formula: If A can do a piece of work in n days, then A’s 1 day’s work =
1
.

n

(A + B + C)’s 1 day’s work =

1
+
1
+
1

=
7
.

24
6
12
24

Formula: If A’s 1 day’s work =
1
,
then A can finish the work in n days.

n

So, all the three together will complete the job in

24
days
=

3
3
days.

7
7

✅ The correct answer is option C.
(B + C)’s 1 day’s work =

1
+
1

=
7
.

9
12
36

Work done by B and C in 3 days =

7
x 3

=
7
.

36
12

Remaining work =

1 –
7

=
5
.

12
12

Now,
1
work is done by A in 1 day.

24

So,
5
work is done by A in

24 x
5

= 10 days.

12
12

✅ The correct answer is option B.
Let 1 man’s 1 day’s work = x and 1 woman’s 1 day’s work = y.

Then, 4x + 6y =
1
and 3x + 7y =
1
.

8
10

Solving the two equations, we get: x =
11
, y =
1

400
400

1 woman’s 1 day’s work =
1
.

400

10 women’s 1 day’s work =

1
x 10

=
1
.

400
40

Hence, 10 women will complete the work in 40 days.

✅ The correct answer is option D.
A’s 1 day’s work =
1
;

15

B’s 1 day’s work =
1
;

20

(A + B)’s 1 day’s work =

1
+
1

=
7
.

15
20
60

(A + B)’s 4 day’s work =

7
x 4

=
7
.

60
15

Therefore, Remaining work =

1 –
7

=
8
.

15
15