M4maths Previous Puzzles

14 Feb 2020 RANK of the word

Rank of the word VALENTINE in the dictionary of words formed by the letters of the word VALENTINE ?

OPtion

1) 81226
2) 81225
3) 81228
4) 81229
5) 81224
6) 81223
7) 81222
8) 81221
9) 81220
10) None of these

Solution

80640 + 0 + 540 + 0 + 24 + 18 + 2 + 1 + 0 + 1 = 81226

Correct Option: 1 Best Solution (3)

13 Feb 2020 Volume

The base of a triangular prism with sides 6 cm 8 cm and 10 cm find the volume (in cm*3) of prism if its height is 15 CM

OPtion

1) 360
2) 324
3) 144
4) 286
5) 364
6) 196
7) 224
8) 350
9) 308
10) None of these

Solution

Area of triangle is 1/2bh

So area of base triangle is is 1/2(6)(8) = 24 cm^2

Area of prism is area of base ×height
=> 24×15=360 cm^3

Correct Option: 1 Best Solution (6)

12 Feb 2020 Work and Time

14 typists can type 4242 pages in 12 hours.Find the average number of pages typed by each typist in an hour.

OPtion

1) 25.00
2) 25.75
3) 26.50
4) 26.25
5) 25.25
6) 27.75
7) 28.50
8) 28.75
9) 29.00
10) None of these

Solution

Total pages typed by 14
typists in 720 minutes/12 hours = 4242

Pages typed by one typist in 12 hours = 303 pages

Pages typed by one typist in one hour = 303/12 = 25.25

Correct Option: 5 Best Solution (0)

11 Feb 2020 Arithmetic

The sum of squares of three successive integers is 20174. Sum of these integers is?

OPtion

1) 256
2) 251
3) 246
4) 296
5) 246
6) 266
7) 206
8) 216
9) 286
10) None of these

Solution

(a-1)^2 + a^2 + (a+1)^2 = 20174
=> a^2 -2a + 1 + a^2 + a^2 + 2a + 1 = 20174
=> 3a^2 + 2 = 20174
=> a^2 = (20174-2)/3 = 6724
=> a = 82
So the 3 numbers are 81, 82 and 83 and their sum is 246

Correct Option: 3 Best Solution (6)

10 Feb 2020 Prime Number

The square of difference between the second and third prime numbers that end with a 9 is:

OPtion

1) 10
2) 20
3) 30
4) 40
5) 50
6) 400
7) 1600
8) 900
9) 100
10) None of these

Solution

The first 3 prime numbers ending in 9 are: 19, 29 and 59

Difference between 2nd and 3rd = 30
Square of difference = 30^2 = 900

Correct Option: 8 Best Solution (7)

07 Feb 2020 Simple Interest

How much time (in years) will it take for an amount of Rs. 450 to yield Rs. 162 as interest at 4.5% per annum of simple interest?

OPtion

1) 2
2) 3
3) 4
4) 3.5
5) 4.5
6) 5.5
7) 5
8) 6.5
9) 8
10) None of these

Solution

SI = PRT/100
162 = 450*4.5*T/100
=> T =8

Correct Option: 9 Best Solution (4)

06 Feb 2020 Volume

Given a pyramid with width 24cm, length 36cm and height 72cm. Find the volume of this pyramid.

OPtion

1) 28736
2) 21736
3) 20736
4) 62208
5) 61208
6) 63208
7) 64208
8) 27736
9) 27786
10) None of these

Solution

Volume of pyramid = lwh/3
=> 24*36*72/3 = 20736

Correct Option: 3 Best Solution (6)

05 Feb 2020 Perfect Square

The difference between the first two perfect squares that end with a 9 is:

OPtion

1) 160
2) 18
3) 27
4) 15
5) 40
6) 26
7) 25
8) 36
9) 30
10) None of these

Solution

9 and 49, difference is 40

Correct Option: 5 Best Solution (5)

04 Feb 2020 Area

Given that total surface area of cylinder is 154 cm². If its radius is 4 cm, find its height (round the decimal value to the nearest hundredth).

OPtion

1) 2.23
2) 2.33
3) 2.43
4) 2.13
5) 2.03
6) 3.13
7) 3.23
8) 3.33
9) 3.43
10) None of these

Solution

T. S. A. =2πrh+2πr2
154 = 2π4 (4+h)
Solving we get h = 2.13 cm

Correct Option: 4 Best Solution (0)

03 Feb 2020 Length

What is the length of the largest rod that can be put in a box of inner dimensions 30 cm, 24 cm and 18 cm?

OPtion

1) 20 √2 cm
2) 40 √2 cm
3) 25 √2 cm
4) 30 √3 cm
5) 15 √2 cm
6) 50 √2 cm
7) 40 √3 cm
8) 30 √2 cm
9) 20 √3 cm
10) None of these

Solution

L= 30 cm , b= 24 cm , h = 18 cm

= √ l*2 + b*2 + h*2
= √ 900 + 576 + 324
= √ 1800 = 30 √2 cm

Correct Option: 8 Best Solution (4)