M4maths Previous Puzzles

17 Feb 2021 Profit

Neeraj buys an old piano for Rs. 6800 and spends Rs. 1200 to repair it. If he sells the piano for Rs. 8600, what is his gain percentage?

OPtion

1) 8.2%
2) 6.8%
3) 6.5%
4) 7.5%
5) 5.5%
6) 8.5%
7) 6.2%
8) 7.8%
9) 9.5%
10) None of the above

Solution

C.P. = 6800 + 1200 = Rs.8000
S.P. = Rs.8600
Gain% = {(S.P. – C.P)/C.P.}X 100
= (8600 – 8000) / 8000 X 100
= 600 X 100 /8000
= 60000/8000
= 7.5 %

Correct Option: 4 Best Solution (3)

16 Feb 2021 Age

The average age of 16 employee in a working for an organization is decreased by 3 months, when an employee aged 17 years replaced by a new employee. Find the age of new employee.

OPtion

1) 14 years
2) 12 years
3) 17 years
4) 16 years
5) 15 years
6) 14 years
7) 13 years
8) 10 years
9) 20 years
10) None of the above

Solution

Age of new employee = Age of replaced employee + Number of employee x change in average
= 17 +16 x (-3/12)
= 17 – 4 = 13 years

Correct Option: 7 Best Solution (3)

15 Feb 2021 Salary

Vijay spends 30% of his salary on food, 15% on his car EMI, 10% on shopping and 20% on parties. If his saving at the end of a month are Rs. 2500, then his monthly salary is?

OPtion

1) Rs. 10000
2) Rs. 7500.50
3) Rs. 8000
4) Rs. 9500
5) Rs. 8200.33
6) Rs. 8400
7) Rs. 9800
8) Rs. 9650
9) Rs. 9400.55
10) None of the above

Solution

Total Spends = 30+15+10+20 = 75%
Saving = 100 – 75 = 25% of his salary = 2500
His monthly salary= 2500/25%
= 2500 x 100/25 = Rs. 10000

Correct Option: 1 Best Solution (3)

12 Feb 2021 Race

In a one kilometer race Anil, Satish and Sonu are the three participants. Anil can give Satish a start 50 m and Sonu a start of 69 m. How many meters start cab Satish give to Sonu?

OPtion

1) 50 m
2) 45 m
3) 25 m
4) 24 m
5) 20 m
6) 30 m
7) 35 m
8) 22 m
9) 28 m
10) None of the above

Solution

When Anil covers 1000 m, Satish covers
(1000-50)= 950m.
and Sonu covers
(1000-69) = 931m.
When Satish covers 950 m, Sonu covers 931 m.
When Satish will cover 1000 m, Sonu will cover = (931/950) x 1000 = 980 m
Therefor Satish can give Sonu a start of 20m.

Correct Option: 5 Best Solution (0)

11 Feb 2021 Number

Find the number, if sum of that number and its square is 2070.

OPtion

1) 46
2) 40
3) 36
4) 42
5) 45
6) 54
7) 50
8) -46
9) -45
10) None of the above

Solution

Let the number be n.
n2 + n = 2070 Eq- i
n2 + n – 2070 = 0
by solving:
(n +46 ) (n – 45) = 0
n = 45

Correct Option: 5 Best Solution (3)

10 Feb 2021 Clock

Shubham runs at a speed of 8m/s. Vijay run behind him after 3 seconds at a speed of 14 m/s. After how much time Vijay will catch the thief?

OPtion

1) 2 seconds
2) 5 seconds
3) 7 seconds
4) 14 seconds
5) 8 seconds
6) 4 seconds
7) 3 seconds
8) 6 seconds
9) 8 seconds
10) None of the above

Solution

Relative speed between Shubham & Vijay = 14- 8
= 6m/s
Vijay lags behind Shubham by 3 seconds at start.
Hence time taken by Vijay to catch Shubham
= Distance covered by Shubham in 3 sec / Relative speed of Vijay
= 8m/s x 3 sec / 6m/s
= 4 seconds

Correct Option: 6 Best Solution (0)

09 Feb 2021 Mensuration

A slab measures (40cm x 20 cm x 25/2 cm). How many slabs will be required for a wall 35 m long, 2 m high and 0.5 m thick?

OPtion

1) 25000
2) 35000
3) 3500
4) 2500
5) 4000
6) 40000
7) 3600
8) 3800
9) 4200
10) None of the above

Solution

Volume of wall = 35 x 2 x 0.5 = 35 cubic meters
Volume of 1 slab = (40/ 100) x(20/100) x (25/200)
= 4/400 Cubic meters
Required numbers of slabs = 35 / (4/400) =35 x 400 / 4
= 3500

Correct Option: 3 Best Solution (2)

08 Feb 2021 STREAMS

Rohan can row upstream at 11kmph and down stream at 13kmph. Find Rohan’s rate in still water.

OPtion

1) 8 kmph
2) 10 kmph
3) 9 kmph
4) 7 kmph
5) 13 kmph
6) 10.5 kmph
7) 11.5 kmph
8) 12 kmph
9) 6 kmph
10) None of the above

Solution

Rate in still water = ½ ( 13 + 11)
= 12kmph

Correct Option: 8 Best Solution (3)

05 Feb 2021 Age

A father is now three times as old as his son. Five years back, he was four time as old as his son. The age of the son is?

OPtion

1) 15
2) 12
3) 18
4) 16
5) 17
6) 14
7) 13
8) 10
9) 20
10) None of the above

Solution

Let the age son be x
Age of father is = 3x
Five years ago-
Age of father = 3x -5
= 4 (x -5)
3x – 5 = 4x -20
X = 20 -5 = 15 years.

Correct Option: 1 Best Solution (4)

04 Feb 2021 Percentage

The salary of Shubham is increased from Rs. 35000 to Rs. 42000. What is the percentage increase in his salary?

OPtion

1) 22%
2) 15%
3) 18%
4) 16%
5) 25%
6) 30%
7) 10%
8) 20%
9) 23%
10) None of the above

Solution

Increase in salary
= 42000 – 35000 = Rs. 7000
Percentage increase in salary = 7000 / 35000 x 100
= 20%

Correct Option: 8 Best Solution (3)