M4maths Previous Puzzles

15 Mar 2012 squares

Total no. of squares in the chess board are

OPtion

1) 1
2) 8
3) 64
4) 85
5) 128
6) 204
7) 256
8) 302
9) 416
10)none of these

Solution

total no. of squares = 1^2 + 2^2 + 3^2 +....... + 8^2
= 204

Correct Option: 6 Best Solution (35)

14 Mar 2012 wheel

A wheel of radius 10 cm. travels a distance in 10 min. A wheel of double the radius will travel the same distance with same speed in :-

OPtion

1) 1 min
2) 5 min
3) 7.5 min
4) 20 min
5) 2.5 min
6) 12.5 min
7) 40 min
8) without providing distance, not possible to find
9) the wheel will take the same time
10) none of these

Solution

since the speed and distance is same so the wheel will take the same time

Correct Option: 9 Best Solution (3)

13 Mar 2012 remainder

On dividing 15^209 by 7, remainder will be

OPtion

1) 1
2) 2
3) 3
4) 4
5) 5
6) 6
7) 0
8) not possible to find

Solution

15^209 = (14+1)^209 = 1+multiple of 7 so remainder will be 1

Correct Option: 1 Best Solution (17)

12 Mar 2012 ab-ba = ?

Difference of the greatest and least positive 9 digit number formed by using the digits 1, 2, 3, 4, 5, 6, 7, 8, 9
Repetition of the digits is not allowed

OPtion

1) 864297532
2) 864197532
3) 854197532
4) 864296532
5) 854296532
6) 864197432
7) 864197542
8) 854397532
9) 846197532
10) none of these

Solution

greatest number = 987654321
least number = 123456789
Difference = 864197532

Correct Option: 2 Best Solution (18)

09 Mar 2012 power puzzle

32*(2^10)*1024 + 64*(2^13)*128 + 16*(2^18)*8 = ?

OPtion

1) 3*(2^25)
2) 1*(2^26)
3) 1*(2^27)
4) 3*(2^26)
5) 1*(2^28)
6) 1*(2^25)
7) 3*(2^27)
8) (2^25)+3*(2^26)
9) 3*(2^25)+(2^26)
10) none of these

Solution

32*(2^10)*1024 + 64*(2^13)*128 + 16*(2^18)*8 = 2^25 + 2^26 + 2^25
= 4*(2^25)
= 2^27

Correct Option: 3 Best Solution (0)

08 Mar 2012 day of festival

The number best suited for today is

OPtion

1) 81151525-815129
2) 71151525-715129
3) 81161625-815128
4) 71161625-715128
5) 81161625-815119
6) 71161625-715119
7) 81151524-815119
8) 71151524-715119
9) 81161625-815129
10) 71161625-715129

Solution

8 1 16 16 25 = H A P P Y
8 15 12 9 = H O L I

Correct Option: 9 Best Solution (0)

07 Mar 2012 integer

The product of three successive positive integers is equal to the sum of average of these three integers and 4. Product of these three integers will be

OPtion

1) 0
2) 6
3) 24
4) 60
5) 120
6) 210
7) 336
8) 504
9) 720
10) none of these

Solution

according to the given condition
(x-1)*x*(x+1) = (x-1+x+x+1)/3 + 4
implies x^3-x = x+4
or x^3-2x-4 = 0
root of this equation = 2
so product = 1*2*3 = 6

Correct Option: 2 Best Solution (0)

06 Mar 2012 infinite sequence

if x = 4/1+(4/1+(4/1+(4/1+(4 ........))))......upto infinite
then x^2 + x = ?

OPtion

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

Solution

According to the given condition x = 4/(1+x) implies that x^2 + x = 4

Correct Option: 4 Best Solution (6)

05 Mar 2012 solve

6 + 2 * (1+2) - (1/3) of 9 = ?

OPtion

1) 1
2) 3
3) 4
4) 6
5) 8
6) 9
7) 10
8) 12
9) 15
10) none of these

Solution

6 + 6 - 3 = 9

Correct Option: 6 Best Solution (17)

02 Mar 2012 probability

There are 8 teams A, B, C, D, E, F, G, H. There winning order is A>B>C>D>E>F>G>H. A tournament of cricket has to be played between all the teams in knockout manner according to the following rules
1) First we have to make two pools of 4-4 teams
2) In every pool there will be two knockout and one semifinal
3) Final will be played between winner of semifinals of both pools.
If it is given that C team is not reached to the final,
Find the probability of having a final between A and B

OPtion

1) 1
2) 1/2
3) 0
4) 3/5
5) 4/5
6) 2/3
7) 3/4
8) 8/15
9) 1/3
10) none of these

Solution

Total no of matches = (8*7*6*5/4*3*2*1)*3*3/2 = 315
Distribution of matches
A and B in any 1 Pool and C in the other pool: total matches of this type = (5*4/2*1)*3*3 = 90
B and C in any 1 Pool and A in the other pool: total matches of this type = (5*4/2*1)*3*3 = 90
C and A in any 1 Pool and B in the other pool: total matches of this type = (5*4/2*1)*3*3 = 90
A, B and C in the same pool : total matches of this type = 45
In first 90 cases C will reach in the final so these are not possible cases
Other 225 cases are possible for rejecting C before final
But in last 45 cases all are in the same pool so B and C both will be eliminated before final so these are non favorable cases
so probability for the required event = 180/225 = 4/5

Correct Option: 5 Best Solution (1)