M4maths Previous Puzzles

20 Jan 2021 Work

A forms a wall in 10 days and B forms it in 15 days. A and B start the work of forming wall together
but after 2 days A leaves the work. How many days are required for making the remaining wall by B?

OPtion

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

Solution

One day work of A = 1/10
One day work of B = 1/15
One day work of A and B = 1/10 + 1/15= 1/6
After 2 days of work remaining work = 1- (2*1/6) = 4/6
No. of days required by B for doing this work = (4/6) / (1/15 = 10

Correct Option: 4 Best Solution (2)

19 Jan 2021 Investment

Kapil Pandey invests in a 20% stock at 180. The interest obtain by him is?

OPtion

1) 8%
2) 8.5%
3) 12.5%
4) 12%
5) 10.5%
6) 11.5%
7) 11.11%
8) 13%
9) 13.5%
10) None of the above

Solution

By investing Rs. 180, income derived = Rs. 20
By investing Rs. 100, income derived = Rs. (20/180 x 100) = Rs. 11.11
Interest Obtain = 11.11%

Correct Option: 7 Best Solution (2)

18 Jan 2021 Race

Raghav beats Vinod by 60 meters or 12 seconds in a km race. Find Raghav’s time over the course.

OPtion

1) 3 min 10 sec
2) 3 min 15 sec
3) 3 min 20 sec
4) 4 min 10 sec
5) 4 min 3 sec
6) 3 min 8 sec
7) 3 min 6 sec
8) 4 min 20 sec
9) 4 min 25 sec
10) None of the above

Solution

As given, Vinod covers 60m in 12 seconds.
Vinod’s time over the course = (12/60 x 1000) = 200 sec.
Raghav’s time over the course = (200 – 12) = 188 seconds
= 188/60 = 3min. 8 seconds.

Correct Option: 6 Best Solution (0)

15 Jan 2021 Percentage

Hemant sold 10 sarees for a total profit of Rs. 460 and 12 sarees for total profit of Rs. 144. At what profit per saree should he sell the remaining 20 sarees so that he gets an average profit of Rs. 18 per saree?

OPtion

1) 7.40
2) 6.80
3) 7.10
4) 7.90
5) 7.80
6) 7.50
7) 7.60
8) 8.00
9) 8.20
10) None of the above

Solution

Total Profit required = Rs, ( 42 x 18)= 756
Profit on 22 sarees = (460+144) = 604
Profit on 20 sarees = (756 – 604) = 152
Average profit on these sarees = (150/20) = Rs.7.60

Correct Option: 7 Best Solution (0)

14 Jan 2021 Perimeter

Arvind has a field in the shape of rectangle. the length of the field is twice its breadth. The breadth is 80m. Find the perimeter of the field.

OPtion

1) 360 m
2) 480 m
3) 520 m
4) 390 m
5) 385 m
6) 460 m
7) 500 m
8) 350 m
9) 450 m
10) None of the above

Solution

Breadth of the field = 80m0
Length of the field = 2 x 80 = 160m
Perimeter of the field = 2 (length + Breadth)
= 2 (160 + 80) = 2 x 240
= 480m

Correct Option: 2 Best Solution (0)

13 Jan 2021 Student

In a school prayer line Amit is 11th from the top and Virendra is 5th from the bottom. If Amit is 5 student ahead of Virendra, Then how many students are there in the line?

OPtion

1) 18
2) 17
3) 16
4) 25
5) 20
6) 22
7) 28
8) 21
9) 13
10) None of the above

Solution

As per given pattern-
Number of student = 10+1+5+1+4
= 21

Correct Option: 8 Best Solution (2)

12 Jan 2021 Percentage

A company market share increased by 10% and subsequently decreased by 10%. What's the percentage change in company shares?

OPtion

1) 10%
2) 5%
3) 15%
4) 20%
5) 4%
6) 1%
7) 2%
8) 6%
9) 8%
10) None of the above

Solution

first increased by 10% and then decreased by 10%
let company market share be 100
10% = 10/100 = 1/10
so 10% of 100 = 10
new share after increase= 100 + 10 = 110..
now 10% of 110 is 11
so new share after decrease is 110 -11 = 99
1 loss on 100 means 1%

Correct Option: 6 Best Solution (2)

11 Jan 2021 Area

Karan walks around a square park whose side is 150m. One day he walked around the park 4 times. How much distance did he walk in a day?

OPtion

1) 3.2 Km
2) 2.8 Km
3) 2.7 Km
4) 3.1 Km
5) 2.9 Km
6) 1.9 Km
7) 2.6 Km
8) 2.4 Km
9) 2.0 Km
10) None of the above

Solution

As given:
Side of square park = 150 m
Perimeter of square park = 150 x 4 = 600m
So by walking 4 time in a day total area cover = 600 x 4 = 2400m = 2.4 km

Correct Option: 8 Best Solution (2)

08 Jan 2021 Time and Work

Vijay can do a certain work in 16 days. Subham is 60% more efficient than Viajy. How many days dose Subham alone take to do the same work?

OPtion

1) 12 days
2) 11 days
3) 14 days
4) 9.5 days
5) 13 days
6) 10 days
7) 15 days
8) 8 days
9) 16 days
10) None of the above

Solution

Ratio of time taken by Vijay and Subham = 160 : 100 = 8 : 5
Suppose Subham alone takes x days to the work = 8 : 5 : : 16 : x
= > 8x = 80
x = 80/8 = 10 days

Correct Option: 6 Best Solution (2)

07 Jan 2021 Volume

If the surface area of a cylindrical tank is 1848 m^2 and the diameter of its base is 14 m, then find the volume of the tank.

OPtion

1) 5000
2) 5500
3) 5350
4) 5460
5) 5450
6) 5390
7) 5875
8) 5900
9) 5535
10) None of the above

Solution

Surface area of cylinder = 2πrh + 2πr2
(2 x 22/7 x 7 x h) + (2 x 22/7 x 7 x 7) = 1848
44h + 308 = 1848
44h = 1540
h = 1540/44 = 35 m
Volume => πr2h = 22/7 x 7 x 7 x 35
= 5390 m3

Correct Option: 6 Best Solution (2)