M4maths Previous Puzzles

10 Jun 2011 run

A man starts to run along a particular direction with a speed of 54 km./hours. After running upto a distance of 100 m, he increases his speed by 50 % of the initial speed, and runs upto 200 m. Total time taken by the man will be

OPtion

1) 10
2) 11.5
3) 12.5
4) 15.5
5) 16
6) 18.5
7) 20.5
8) 21
9) 22.5
10) None of these

Solution

54 km./hour = 54*5/18 = 15 m/s
81 km./hour = 81*5/18 = 22.5 m/s
so total time = (100/15)+(200/22.5) = 15.5 sec.

Correct Option: 4 Best Solution (0)

09 Jun 2011 sequence

14, 312, 536, 7108, ....
next number will be

OPtion

1) 21414
2) 23456
3) 8244
4) 9324
5) 10324
6) 12396
7) 21346
8) 8234
9) 11234
10) None of these

Solution

1-4, 3-12, 5-36, 7-108, 9-324

Correct Option: 4 Best Solution (9)

08 Jun 2011 arrangement

How many words can be formed by the letters of the word SULTAN, if the starting and end letters of the word are vowels used in word SULTAN.

OPtion

1) 48
2) 720
3) 24
4) 2
5) 120
6) 4320
7) 1
8) 16
9) 6
10) None of these

Solution

Total methods are (2*1)*(4*3*2*1) = 48

Correct Option: 1 Best Solution (6)

07 Jun 2011 L.C.M.

l.c.m. of x and 16 is same as h.c.f. of 240 and 192. How many values of x are possible.

OPtion

1) 9
2) 8
3) 7
4) 6
5) 5
6) 4
7) 3
8) 2
9) 1
10) None of these

Solution

Possible solutions are 48, 24, 12, 6, 3

Correct Option: 5 Best Solution (5)

06 Jun 2011 rank

Rank of word "MADAN" in the dictionary made by letters of the same word.

OPtion

1) 36
2) 37
3) 38
4) 39
5) 40
6) 41
7) 42
8) 43
9) 44
10) None of these

Solution

MADAN, ordered arrangement is AADMN, Total words possible = 60
3*(60/5) + 0*(12/4) + 1*(2*3/3) + 0*(2/2) + 1 = 39
Here 3 is for 3 letters before the starting letter of the word MADAN, similarly for others.

Correct Option: 4 Best Solution (2)

03 Jun 2011 coin

How many methods are possible to get a total amount of 10 rupee in 18 coins. A lot of 25 paisa, 50 paisa and 1 rupee coins are available. Use of every type of coin is not compulsory.

OPtion

1) 1
2) 2
3) 3
4) 4
5) 5
6) 6
7) 7
8) 8
9) 9
10) None of these

Solution

x(0.25) + y(0.50) + (18-x-y)(1) = 10
On solving this equation, we get 3x + 2y = 32
Possible solutions are
(0,16,2), (4,10,4), (8,4,6), (2,13,3), (6,7,5), (10,1,7)

Correct Option: 6 Best Solution (1)

02 Jun 2011 ace and king

Two cards are selected at random from a deck of 52 cards. What will be the probability to get an ace and a king of different suits.

OPtion

1) 1/221
2) 2/221
3) 3/221
4) 4/221
5) 8/221
6) 10/221
7) 12/221
8) 15/221
9) 20/221
10) None of these

Solution

Probability = (4/52)*(3/51)*2 = 2/221

Correct Option: 2 Best Solution (1)

01 Jun 2011 unknown integer

An integer is such that the square of one fourth of the integer is equal to one less than the sum of half of the integer and one third of the integer. Integer is

OPtion

1) 4
2) 8
3) 12
4) 16
5) 20
6) 24
7) 28
8) 32
9) 36
10) None of these

Solution

(x/4)^2 = (x/2) + (x/3) - 1

Correct Option: 3 Best Solution (0)

31 May 2011 percentage

12 % of a number is 6 less than 10 % of twice of 2 more than that number.The number is

OPtion

1) 45
2) 60
3) 70
4) 84
5) 96
6) 102
7) 106
8) 116
9) 120
10) None of these

Solution

12x/100 = 10*2(x+2)/100 - 6
on solving we get x = 70

Correct Option: 3 Best Solution (3)

30 May 2011 sequence

Next number of the sequence
4, 20, 5, 25, 25/4, 125/4, ....
will be

OPtion

1) 2
2) 5
3) 25
4) 125/16
5) 225/8
6) 20
7) 100/9
8) 175/16
9) 155/16
10) None of these

Solution

sequence formula is
*5, /4, *5, /4, *5, /4

Correct Option: 4 Best Solution (4)