M4maths Previous Puzzles

06 Jan 2021 Train & Speed

A 150m meters long train takes 10 seconds to cross Atul walking at 5 kmph in a direction opposite to that of the train. Find the speed of train.

OPtion

1) 49 kmph
2) 52 kmph
3) 55 kmph
4) 56 kmph
5) 62 kmph
6) 51 kmph
7) 57 kmph
8) 48 kmph
9) 53 kmph
10) None of the above

Solution

Speed of train relative to man = ( X + 5)Kmph
= (X + 5) x 5/18 m/s
150/ (X + 5) x (5/18) = 10
(150 x 18)/ (X + 5) 5 = 10
50X + 250 = 2700
X = 2450/50 = 49 Kmph

Correct Option: 1 Best Solution (3)

05 Jan 2021 Age

Himanshu is 55 years old and Rohan is 65 years old. How many years ago was the ratio of their ages 4 : 6 ?

OPtion

1) 30 years
2) 32 years
3) 28 years
4) 35 years
5) 40 years
6) 22 years
7) 26 years
8) 38 years
9) 34 years
10) None of the above

Solution

Suppose the ratio was 4 : 6, x years ago.
Then,
(55 – x)/ (65 – x) = 4/6
6 (55 – x) = 4(65 – x)
330 – 6x = 260 – 4x
2x = 70
x = 70/2 = 35 years.

Correct Option: 4 Best Solution (2)

04 Jan 2021 Partnership

Aman, Balveer and Chandan hired a car for Rs. 820 and used it for 4, 6 and 10 hours respectively. Hire charge paid by Balveer were?

OPtion

1) Rs. 250
2) Rs. 260
3) Rs. 246
4) Rs. 240
5) Rs. 235
6) Rs. 244
7) Rs. 248
8) Rs. 258
9) Rs. 255
10) None of the above

Solution

Aman : Balveer : Chandan
= 4 : 6 : 10
Hire charges paid by Balveer = (820 x 6/20) = Rs. 246

Correct Option: 3 Best Solution (3)

01 Jan 2021 Difference

9 packet of rice of the same weight weigh 2.7Kg. 1 bowl of rice weighs 700g. How much heavier is 1 bowl of rice than 1 packet of rice?

OPtion

1) 250g
2) 225g
3) 300g
4) 370g
5) 500g
6) 900g
7) 600g
8) 400g
9) 450g
10) None of the above

Solution

Weight of 9 packets of rice = 2.7Kg= 2700g
Weight of 1 packet of rice = 2700/9= 300g
Weight of 1 bowl of rice = 700g
Weight difference in 1 bowl and 1 packet of rice = 700-300= 400g

Correct Option: 8 Best Solution (2)

31 Dec 2020 Radius

A 22m wide circular platform has inner circumference of 880m. Find the radius of the outer circle?

OPtion

1) 175m
2) 162m
3) 155m
4) 152m
5) 165m
6) 189m
7) 84m
8) 102m
9) 110m
10) None of the above

Solution

Let the radius be r meter.
Then as per given condition- 2πr= 880
Hence, r = 880/2π
= (880 x 7/44)m
r = 140m
Hence, Radius of outer circle = 140+22 = 162m

Correct Option: 2 Best Solution (2)

30 Dec 2020 Storage

2626 bags of marbles can store in a store room. If each bag contains 49 marbles, then find the total number of marbles (Approximate value) stored in the store room if it is filled 80%?

OPtion

1) 128674
2) 128666
3) 102000
4) 118674
5) 102950
6) 105939
7) 102939
8) 102674
9) 102848
10) None of the above

Solution

Total no of bags can be store = 2626
Number of marbles in each bags = 49
Hence, total number of marbles can stored in the stored room = 2626 x 49
= 128674
80% 0f 128674 = 128674*0.80
= 102939.2

Correct Option: 7 Best Solution (3)

29 Dec 2020 Permutation & Combination

When Manan arrives in New Delhi, he has 8 shops to see, but he has time only to visit 6 of them. In how many different ways can he arrange his schedule in New Delhi?

OPtion

1) 20260
2) 20360
3) 21160
4) 22165
5) 20165
6) 20160
7) 22160
8) 25160
9) 23000
10) None of the above

Solution

He can arrange his schedule in 8 P6 = 8× 7 × 6 × 5 × 4 × 3 = 20160 ways.

Correct Option: 6 Best Solution (3)

28 Dec 2020 Cold Drink

Kapil pours 3L 549 mL of cold drink equally into 7 glasses. How much of cold is required to fill 11 glasses of same size?

OPtion

1) 6 L
2) 5.2 L
3) 6.4 L
4) 5.57 L
5) 5.45 L
6) 6.23 L
7) 5.69 L
8) 5.68 L
9) 6.87 L
10) None of the above

Solution

Total quantity of cold drink is = 3L 549 mL = 3.549 L
Quantity of cold drink in 1 glass is = 3.549/7 = 507 mL
So, quantity required to fill 11 glasses = 507 x 11 = 5577 mL = 5.57 L

Correct Option: 4 Best Solution (0)

25 Dec 2020 Length

Ms Pooja had 20.80 m of cotton piece. See cut 7 smaller pieces each of length 0.81 m from it. How many meters of cotton were left?

OPtion

1) 5.67 m
2) 16.15 m
3) 14.15 m
4) 15.50 m
5) 16.50 m
6) 14.50 m
7) 15.15 m
8) 16
9) 12.37
10) None of the above

Solution

Total length of cotton = 20.80 m
Length of 1 small piece of cotton = 0.81 m
Length of 7 small pieced of cotton = 7 x 0.81 = 5.67 m
Hence length of remaining cotton = 20.80 – 5.67 = 15.15 m

Correct Option: 7 Best Solution (2)

24 Dec 2020 Expanse

The mean expanse of a batch of 20 boys is Rs.8200 per month and that for a batch of 30 girls is Rs.7200 per month. What is the combined expanse?

OPtion

1) 8000
2) 8200
3) 7800
4) 7700
5) 7600
6) 7500
7) 8300
8) 7900
9) 7550
10) None of the above

Solution

As given n1 = 20, n2 = 30, x-bar 1= Rs.8200 and x-bar 2 = Rs.7200
Hence, the combined mean expanse per month is
X-bar = {n1 X(x-bar1) + n2 X (x-bar2)}/ n1+n2
= (20x8200 + 30x7200) / 20+30
=164000 + 216000 / 50
= 380000/50
= Rs. 7600

Correct Option: 5 Best Solution (0)