M4maths Previous Puzzles

31 Mar 2021 Train & Speed

A 440-metre-long train crosses a platform twice of its length In 50 seconds. What Is the speed of the train in km/hour?

OPtion

1) 90.55 kmph
2) 95.50 kmph
3) 95.04 kmph
4) 92.5 kmph
5) 100 kmph
6) 104.04 kmph
7) 98.30 kmph
8) 97.25 kmph
9) 102.2 kmph
10) None of the above

Solution

Speed of train = Length of (train + Platform)/Time taken
= 440 + (2 x 440) / 50
= 26.4 Meter/sec.
= 95.04 kmph

Correct Option: 3 Best Solution (2)

30 Mar 2021 Profit

Jugmohan sold his old cell phone for Rs 1,850 and earned a profit of 25 percent. At what price did Jugmohan buy the Cell phone?

OPtion

1) Rs 1250
2) Rs 1380
3) Rs 1260
4) Rs 1400
5) Rs 1440
6) Rs 1480
7) Rs 1520
8) Rs 1500
9) Rs 1560
10) None of the above

Solution

C.P. = 100/(100+Profit per cent)×S.P.
=100/125×1850= Rs.1480

Correct Option: 6 Best Solution (2)

29 Mar 2021 AGE

The age of Ramesh and Suresh differ by 20 years. If 4 years ago the age of Suresh be 3 times as old as the Ramesh, Find their present Suresh.

OPtion

1) 36
2) 35
3) 32
4) 39
5) 29
6) 30
7) 33
8) 34
9) 28
10) None of the above

Solution

Let the age of the Ramesh is X years.
Then the age of the Suresh will be= (X + 20) Years
As given:- 3 (X-4) = (X + 20 – 4)
3X – 12 = X + 16
2X = 28, X = 14 Years
Hence the age of Suresh Will be = 14+20 = 34 Years.

Correct Option: 8 Best Solution (2)

26 Mar 2021 Percentage

Akshay as a quality inspector rejects 0.08% of the vehicles as defectives. How many vehicles will be examined to project?

OPtion

1) 2200
2) 2500
3) 2300
4) 2800
5) 2700
6) 2600
7) 2450
8) 2350
9) 2250
10) None of the above

Solution

Let the number of vehicles to be examined is X.
Then, 0.08% of x = 2
[( 8/100) x (1/100) x X] = 2
X = [(2 x 100 x 100)/8] = 2500

Correct Option: 2 Best Solution (0)

25 Mar 2021 Discount

Raman buys a single egg for ₹5. If he were to buy a dozen eggs, he would have to pay a total amount of ₹50. What would be the approximate per cent discount Raman would get on buying a dozen apples?

OPtion

1) 20%
2) 22%
3) 18%
4) 14%
5) 16%
6) 19%
7) 25%
8) 30%
9) 17%
10) None of the above

Solution

Cost of 1 egg = ₹5
Cost of 1 dozen eggs = 12 x 5 = ₹60
Discount = 60 – 50 = ₹10
% discount = 10 * 100/60 = 16.66 = 17%

Correct Option: 9 Best Solution (2)

24 Mar 2021 Ratio

The area of a square is 2116 sq. cm. What is the respective ratio between the length and the breadth of a rectangle whose length is ¼ of the side of the square and breadth is 8 cm less than the side of the square?

OPtion

1) 5 : 8
2) 5 : 18
3) 16 : 8
4) 12 : 36
5) 11.5 : 38
6) 11.5 : 36
7) 12 : 38
8) 12 : 30
9) 14 : 36
10) None of the above

Solution

Given, a2 = 2116 sqcm.
So, a = √2116 = 46cm
As per condition 1, length of the rectangle = ¼ x 46 = 11.5 cm
As per condition 2, breadth of the rectangle = 46 – 8 = 38 cm
Hence ratio will be- 11.5: 38

Correct Option: 5 Best Solution (3)

23 Mar 2021 PROBABILITY

It is given that in a group of 5 Executives in an organisation, the probability of 3 of them not having the same birthday is 0.962. What is the probability that the 3 executives have the same birthday?

OPtion

1) 0.038
2) 0.008
3) 0.030
4) 0.058
5) 0.010
6) 0.062
7) 0.050
8) 0.962
9) 0.018
10) None of the above

Solution

Let the event wherein 3 executives having the same birthday be E
Given, P(E) = 0.962
We know,
P(E)+P(not E) = 1
Or, P(not E) = 1–0.962 = 0.038
∴ The probability that the 3 executives have the same birthday is 0.038.

Correct Option: 1 Best Solution (3)

22 Mar 2021 Survey

A survey shows that 64% of the Indians like bikes, whereas 58% like scooters.
What percentage of the Indians like both bikes and scooters?

OPtion

1) 42%
2) 44%
3) 46%
4) 26%
5) 24%
6) 22%
7) 28%
8) 34%
9) 34%
10) None of the above

Solution

Let P & Q denote the sets of Indians who like bikes and scooters respectively. Then
n(P ) = 64, n(Q) = 58 and n(P ∩ Q) = 100.
We know that n( P ∩ Q) = n(P) + n(Q) – n( P ∩ Q )
= 64 + 58 – 100 = 22.
Hence, 22% of the Indians like both bikes and scooters.

Correct Option: 6 Best Solution (3)

19 Mar 2021 Interest

Find the rate of interest if the amount owed after 9 months is Rs.1200, borrowed
amount being Rs.1000.

OPtion

1) 25%
2) 26%
3) 26.66%
4) 25.55%
5) 30%
6) 30.50%
7) 28.50%
8) 27%
9) 27.50%
10) None of the above

Solution

We know A = P + Pit
i.e. 1200 = 1000 + 1000 × i × 9/12
200 = 750 i
i = 200/750 = 26.66%

Correct Option: 3 Best Solution (2)

18 Mar 2021 Partnership

Sanjay & Sunil enters into a partnership. Sanjay invests Rs. 2000 and Sunil Rs. 3000. After 6 months, Sunil withdrew from the business. At the end of the year, the profit was Rs. 4200. How much would Sunil get out of this profit.

OPtion

1) 2200
2) 2100
3) 1800
4) 1550
5) 1500
6) 1600
7) 2400
8) 2250
9) 2300
10) None of the above

Solution

One person’s (Investment X Time) : Another person’s (Investment X Time)
Therefore the ratio in which Sanjay & Sunil would share their profit is-
2000 (12) : 3000 (6) = 4:3
Hence Sunil receives (3/7)*4200 = Rs. 1800

Correct Option: 3 Best Solution (2)