M4maths Previous Puzzles

05 Apr 2019 Lift

Jack enters a lift on the 24th floor, which is going up @ 51 floors/min speed. At the same time Jill

enters another lift on the 246th floor which is going down @ 60 floors/min speed. At what floor will

they be together?

OPtion

1) 102
2) 126
3) 124
4) 128
5) 125
6) 129
7) 120
8) 130
9) 123
10) None of these

Solution

Relative Speed = 51+60 = 111 floors/min
Relative Distance = 246 - 24 = 222 floors

Time to cover 222 floors = 222*60/111 = 120 seconds

Floors travelled by Jack in 120 seconds = (51/60)*120 = 102
Floors on which they will meet = 24 + 102 = 126th
Option 2)

Correct Option: 2 Best Solution (0)

04 Apr 2019 Rank of the word

Find Rank of the word LUMINESCEN in the dictionary of words formed by the letters of the word LUMINESCEN

OPtion

1) 441221
2) 444221
3) 449221
4) 442221
5) 445221
6) 448221
7) 447221
8) 446221
9) 443221
10) None of these

Solution

Answer: 449221

luminescen
Lets arrange the letters alphabetically = ceeilmnnsu

Words starting with c = 9!/(2!*2!) = 90720
Words starting with e = 9!/(2!) = 181440
Words starting with i = 9!/(2!*2!) = 90720
Words starting with lc = 8!/(2!*2!) = 10080
Words starting with le = 8!/(2!) = 20160
Words starting with li = 8!/(2!*2!) = 10080
Words starting with lm = 8!/(2!*2!) = 10080
Words starting with ln = 8!/(2!) = 20160
Words starting with ls = 8!/(2!*2!) = 10080

Words starting with luc = 7!/(2!*2!) = 1260
Words starting with lue = 7!/(2!) = 2520
Words starting with lui = 7!/(2!*2!) = 1260

Words starting with lumc = 6!/(2!*2!) = 180
Words starting with lume = 6!/(2!) = 360

Words starting with lumic = 5!/(2!*2!) = 30
Words starting with lumie = 5!/(2!) = 60

Words starting with luminc = 4!/(2!) = 12

Words starting with luminec = 3! = 6
Words starting with luminee = 3! = 6
Words starting with luminen = 3! = 6
Words starting with luminescen = 1

Sum of all = 449221

Option 3)

Correct Option: 3 Best Solution (3)

03 Apr 2019 Percentage

The cost of manufacturing a popular model car is made up of three items:cost of raw material,labour and overheads- in a year the cost of three items were in the ration of 5:4:2 respectively, next year the cost of the raw material rose by 10% ,labour cost increased by 8% but overhead reduced by 5%.then %increase in the price of the car ?

OPtion

1) 6.055
2) 6.454
3) 7.545
4) 6.545
5) 7.454
6) 6.055
7) 6.444
8) 7.555
9) 6.333
10) None of these

Solution

Let the cost of raw material, labour and overheads be 50, 40 and 20

In a given year total cost is : 50 + 40 + 20 = 110
Cost next year = 55 + 43.2 + 19 = 117.2

% increase = (7.2/110)*100 = ~6.545%

Correct Option: 4 Best Solution (9)

02 Apr 2019 Daily Wages

The ratio of daily wages of three workers Pappu, Khoju and Mauju are in ratio 7:6:4 and Pappu gets daily Rs 84 more than Mauju, what is the sum of their daily wages?

OPtion

1) 28
2) 280
3) 160
4) 390
5) 476
6) 430
7) 450
8) 480
9) 475
10) None of these

Solution

Let their wages 7x, 6x and 4x

As per question 7x -4x = 84
=> 3x = 84 => x = 28

Sum of ages 7x+6x+4x = 17x = 17* 28 = 476

Correct Option: 5 Best Solution (0)

01 Apr 2019 Percentage

A persons salary iis decreased by steps of 25%, 15% and 10%. What will be the percentage decrease, if the salary is decreased in a single shot?

OPtion

1) 40.625
2) 42.625
3) 41.625
4) 43.625
5) 44.625
6) 45.625
7) 39.625
8) 38.625
9) 37.625
10) None of these

Solution

Decreased salary = = 100 * 0.75 * 0.85 * 0.9 = 57.375
Single shot percentage = 100 - 57.375 = 42.625

Correct Option: 2 Best Solution (0)

29 Mar 2019 Distance Traveled

Consider a well of 116 mt depth and a frog at the bottom of the well. It climbs 9 mt in day time and slides down 5 mt during night.
How many days it needs to climb out of the well?

OPtion

1) 29
2) 30
3) 28
4) 27
5) 26
6) 31
7) 32
8) 25
9) 27.5
10) None of these

Solution

At the end of first day + night frog would have climbed = 9 - 5 = 4 m
At end of 27 days + night he would have climbed = 27*4 = 108 mts
On 28th day frog can climb 9 mts which will bring it out of the well.
So answer is 28 days.

Correct Option: 3 Best Solution (4)

28 Mar 2019 Probability

There are 9 positive and 5 negative numbers. Four numbers are chosen at random and multiplied.the probability that the product is positive is:

OPtion

1) 505/1001
2) 501/1001
3) 511/1001
4) 509/1001
5) 503/1001
6) 499/1001
7) 491/1001
8) 493/1001
9) 481/1001
10) None of these

Solution

Products of four numbers would be positive if all 4 are positive or all 4 are negative or two are positive and 2 are negative
PPPP P 9C4/14C4 = 126/1001
NNNN P 5C4/14C14 = 5/1001
PPNN P 9C2*5C2/14C4 = 360/1001

Probability = 491/1001

Correct Option: 7 Best Solution (0)

27 Mar 2019 Area

If the diagonal of a rectangle is 18cm long and its perimeter is 48 cm. Find the area of the rectangle.

OPtion

1) 100 sq.cm
2) 112 sq.cm
3) 110 sq.cm
4) 116 sq.cm
5) 126 sq.cm
6) 120 sq.cm
7) 130 sq.cm
8) 140 sq.cm
9) 105 sq.cm
10) None of these

Solution

Let length = x and breadth = y then

2(x+y) = 48 => x+y = 24
x²+y² = 18² = 324
now (x+y)² = 24²
=> x²+y²+2xy= 576
=> 324+ 2xy = 576
=> xy = 126

Area = xy = 126 sq.cm

Correct Option: 5 Best Solution (4)

26 Mar 2019 Cost Price

If a tomato and potato together cost Rs. 54.00, a radish and a tomato cost Rs.27.00 and an potato cost Rs.27.00 more than a radish or a tomato then which of the following can be the price of a tomato

OPtion

1) 25
2) 24.5
3) 27
4) 28
5) 26.5
6) 13.5
7) 14
8) 15
9) 14.5
10) None of these

Solution

t+p=54
t+r=27
condition
p=t+27
p=r+27

t+t+27 = 54
t = 13.5

Correct Option: 6 Best Solution (0)

25 Mar 2019 Age

The present age of a brother is 3 years more than four times the age of his sister. Three years hence, brother’s age will be 6 years more than twice the age of the sister. Find the present age of the brother.

OPtion

1) 9
2) 12
3) 10
4) 15
5) 16
6) 14
7) 11
8) 18
9) 13
10) None of these

Solution

Let the sister’s present age be ‘n’ years.
=> brother’s present age = (4n + 3) years
So, according to the question
(4n + 3 + 3) = 2 (n + 3) + 6
=> 4n + 6 = 2n + 12
=> n = 3
Hence, brother’s present age = (4n + 3) = 15 years

Correct Option: 4 Best Solution (0)