M4maths Previous Puzzles

23 May 2018 Work & Time

If 7 men and 9 women can do a piece of work in 13 days and 5 men and 7 women can do it in 17 days, how

many days will 6 men and 11 women take to do half of it?

OPtion

1) 13.66
2) 10.50
3) 11.33
4) 12.33
5) 12.5
6) 5.33
7) 6.66
8) 11.00
9) 13.33
10) None of these

Solution

Let a man's daily work is x units and that of a woman is y units.
So total amount of work, W = 13(7x + 9y) = 17(5x + 7y)

Solving we get, 91x - 85x = 119y - 117y
=> 6x = 2y
=> y = 3x


Now, 7 x + 9 y can do work in 13 days.
So, 7x + 27x can do work in 13 days.
So, 34 x can do work in 13 days.

Now, 6x + 11y = 6x + 33x = 39x

Hence, if 34 x can do work in 13 days, 39x can do work in (13*34)/39 = 11.33 days.

Time taken to do half of the work= 11.33/2 = 5.665

Option 10)

Correct Option: 10 Best Solution (0)

22 May 2018 Logarithm

If log 27 = 1.935, then the value of log 9 is

OPtion

1) 0.954
2) 0.645
3) 1.290
4) 0.9675
5) 1.391
6) 0.867
7) 1.135
8) 0.795
9) 1.375
10) None of these

Solution

Log 27 = Log 3^3 = 3Log3 = 1.935
=> Log3 = 1.935/3 = 0.645

Log 9 = Log3^2 = 2 Log3 = 2*(0.645) = 1.29

Correct Option: 3 Best Solution (0)

21 May 2018 Simple Interest

A sum of money at simple interest amounts to Rs. 9037 in 4 years and to Rs. 11982 in 9 years. The sum is:

OPtion

1) 6601
2) 6618
3) 6687
4) 5681
5) 5601
6) 6681
7) 5687
8) 5881
9) 6689
10) None of these

Solution

S.I. for 5 years = Rs. (11982-9037) = Rs. 2945
S.I. for 1 year = Rs. 2945/5 = 589


S.I. for 4 years = Rs. 4*(589) = 2356
Principal = Rs. (9037 - 2356) = Rs. 6681

Correct Option: 6 Best Solution (3)

18 May 2018 Probability

An alphanumeric character is randomly selected from following sentence:
"Do not linger to gather flowers to keep them,

but walk on, for flowers will keep themselves blooming all your way."

What is the probability that its an vowel or letter T?
Note: Alphanumeric character means alphabet or number. Space and other characters should be ignored.

OPtion

1) 37/91
2) 37/90
3) 38/91
4) 38/90
5) 40/91
6) 4/9
7) 41/91
8) 3/7
9) 36/91
10) None of these

Solution

Sentence = Do not linger to gather flowers to keep them,

but walk on, for flowers will keep themselves blooming all your way.


Total number of alphanumeric character in the sentence = 91
Total Number of vowels = 32

And Total number of Ts = 7

Probability = (32+7)/91 = 39/91 = 3/7

Option 8)

Correct Option: 8 Best Solution (0)

17 May 2018 Average

In the first 4 overs of a T20 cricket match, the run rate was only 5.5. What should be the run rate in the remaining 16 overs to reach the target of 194 runs?

OPtion

1) 10.00
2) 10.25
3) 9.50
4) 10.075
5) 9.25
6) 10.50
7) 9.75
8) 11.00
9) 10.08
10) None of these

Solution

Runs scored in the first 4 overs = 5.5 × 4 = 22 Total runs = 194 Remaining runs to be scored = 194 - 22 = 172
Remaining overs = 16
Run rate needed = 172 / 16 = 10.75

Correct Option: 10 Best Solution (0)

16 May 2018 Speed and Distance

Veerbhadhran could either walk or drive to office. The time taken to walk to the office is 14 times the driving time. One day, his wife took the car making him walk to office. After walking 1 km, he reached a temple when his wife called to say that he can now take the car. Veerbhadhran figured that continuing to walk to the office will take half as long as walking back home and then driving to the office. Calculate the distance between the temple and the office in KMs.

OPtion

1) 14/9
2) 5/9
3) 11/9
4) 13/9
5) 10/9
6) 17/9
7) 16/9
8) 8/9
9) 7/9
10)None of these

Solution

Suppose the distance between his home and office is x km. Then, distance between his office and temple is (x – 1) km.
If he walks at a speed of y km/hr. Then his driving speed = 14y km/hour, as he is 14 times faster in car.

Then,
Time Taken To walk back Home from temple + Time Taken to drive to office from home = 2* Time taken to walk to office from temple
1/y + x/14y = 2*(x – 1)/y
Or, 1 + x/14 = 2x – 2
or 27x/14 = 3
Or, x = 14/9
Finally, x – 1 = 14/9 - 1 = 5/9
Option 2)

Correct Option: 2 Best Solution (0)

15 May 2018 Simple Interest

A sum of money at simple interest amounts to Rs. 11516 in 5 years and to Rs. 14203 in 10 years. The sum is:

OPtion

1) 8809
2) 8839
3) 8029
4) 8819
5) 8329
6) 8689
7) 8929
8) 8829
9) 6889
10) None of these

Solution

S.I. for 5 years = Rs. (11982-9037) = Rs. 2687
S.I. for 1 year = Rs. 2687/5

S.I. for 5 years = Rs. 2687
Principal = Rs. (11516 - 2687) = Rs. 8829

Correct Option: 8 Best Solution (0)

14 May 2018 Profit and Loss

A vendor bought bananas at the rate of 6 for 24 rupee. How many for 24 rupees must he sell to gain 20 %?

OPtion

1) 4.00
2) 4.25
3) 4.50
4) 4.75
5) 5.25
6) 5.00
7) 5.50
8) 5.75
9) 5.80
10) None of these

Solution

Cost Price of 1 Banana = 4 Rupees
Selling Price of 1 Banana = 4*120/100 = 4.8 Rupees

Number of banana's he can sell in 24 rupees = 24/4.8 = 5

Correct Option: 6 Best Solution (0)

11 May 2018 Volume

13 solid spheres of radius 4 m, 14 solid cones of radius 3 m, height 5 m and 17 solid cylinders of radius 2m and height 6m are melted to form a bigger solid cone of height 1500 cm. What is the radius of this bigger solid cone in meters?

OPtion

1) 10.59
2) 18.59
3) 10.73
4) 10.90
5) 18.95
6) 18.64
7) 17.77
8) 17.95
9) 17.09
10) None of the above

Solution

Vol of Sphere = (4/3)*Pi*r^3
Vol. of Cylinder = Pi*r^2*h
Vol. of cone = (1/3)*Pi*r^2*h


Volume of 13 solid spheres = 13 * 268.19 = 3486.48

Volume of 14 solid cones = 14 * 47.14 = 660


Volume of 17 solid cylinders = 17 * 75.43 = 1282.29

Total Volume = 5428.762 m

Radius of larger cone = [(3*Total Volume /Pi*h)]^1/2 = ~ 18.59 m

Correct Option: 2 Best Solution (0)

10 May 2018 Find the product

Find the product of twice of mean, median and one third of mode (i.e. you need to find 2*mean* median * mode/3) for the following list of values?
55 55 45 36

66 31 50

36 68 28 36

OPtion

1) 49860
2) 149860
3) 74520
4) 48954
5) 148075
6) 49070
7) 24840
8) 49680
9) 17820
10) None of these

Solution

Mean = Sum of nos. / Count of numbers = 506/11 = 46
Median = Middle term when number are arranged in ascending order = 45
Mode = Number which is present maximum number of times = 36
Product = 2*46*45*36/3 = 49680

Option 8)

Correct Option: 8 Best Solution (0)