M4maths Previous Puzzles

19 Aug 2010 Number of 25 paisa coins?

There are 40 coins, whose total cost is 19.25 rupee. If there are 3 category of coins 25 paisa,
50 paisa, 1 rupee. Then total number of 25 paisa coins is Given that 1 rupees coins are 8.

OPtion

1) 22
2) 18
3) 17
4) 19
5) 24
6) 26
7) 28
8) 15
9) 12
10) 10

Solution

distribution is
19*0.25 = 4.75
13*0.50 = 6.50
8*1.00 = 8.00

Correct Option: 4 Best Solution (8)

18 Aug 2010 Find the sum of x and y

The sum of 2 integers x and y is 10. Total number of all the possible doublets (x, y) are

OPtion

1) 8
2) 2
3) 4
4) 9
5) 12
6) 11
7) 20
8) 36
9) 45
10) Infinite

Solution

since integers may be negative hence infinite many solutions are possible.

Correct Option: 10 Best Solution (2)

17 Aug 2010 Son and father age

A father said to his son that he was thrice of his age 15 years before and will be twice of his age
10 years hence. Difference of the ages of father and son is

OPtion

1) 24
2) 40
3) 32
4) 35
5) 50
6) 12
7) 22
8) 34
9) 28
10) 38

Solution

Let the age of father is f and that of son is s at present
According to the given conditions
f - 15 = 3 (s-15) => f – 3s = -30 (i)
f + 10 = 2 (s+10) => f – 2s = 10 (ii)
On solving (i) and (ii), we get f = 90; s = 40

Correct Option: 5 Best Solution (0)

16 Aug 2010 Find the sum

1-2+3-4+5-6+.......... +999-1000 = ?

OPtion

1) +650
2) -650
3) +500
4) -500
5) +840
6) -840
7) +770
8) -770
9) +1000
10) -1000

Solution

(1-2)+(3-4)+(5-6)+........ +(999-1000) =
-1 -1 -1 - 1
= -500

Correct Option: 4 Best Solution (24)

13 Aug 2010 Which one is greater?

Which one is greater?

OPtion

1) 400 kilometer/ day
2) 6 meter/ second
3) 20 kilometer/ hour
4) 400 meter/ minute
5) 500000 meter/ day
6) 0.005 kilometer/ second
7) 0.6 kilometer/ minute
8) 23000 meter/ hour
9) 550 centimeter/ second
10) 40000 centimeter/ minute

Solution

20 kilometer/ hour = 20*1000/3600 = 200/36 = 5.555 m/s
400 meter/ minute = 400/60 = 40/6 = 6.666 m/s
500000 meter/ day = 500000/86400 = 5000/864 = 5.787 m/s
0.005 kilometer/ second = 0.005*1000 = 5 m/s
0.6 kilometer/ minute = 0.6*1000/60 = 10 m/s
400 kilometer/ day = 400*1000/86400 = 4000/864 = 4.63 m/s
23000 meter/ hour = 23000/3600 = 6.389 m/s
550 centimeter/ second = 550/100 = 5.5m/s
40000 centimeter/ minute = 40000/(100*60) = 40/6 = 6.666 m/s

Correct Option: 7 Best Solution (1)

12 Aug 2010 what will be the next

9, 7, 7, 9, 13 ?

OPtion

1) 7
2) 9
3) 13
4) 11
5) 10
6) 4
7) 24
8) 17
9) 19
10) Not in the option

Solution

9 , 16, 25, 36, 49, 64
9, 7, 7, 9, 13, 10 (sum of digits)

Correct Option: 5 Best Solution (22)

11 Aug 2010 Find the ratio

60% of a number is equal to twice of the other number. Ratio of the numbers is?

OPtion

1) 4 : 1
2) 1 : 5
3) 8 : 7
4) 5 : 3
5) 2 : 3
6) 3 : 4
7) 10 : 3
8) 5 : 2
9) 7 : 9
10) 9 : 4

Solution

(60x/100) = 2y
x/y = 200/60
= 20/6 = 10/3

Correct Option: 7 Best Solution (13)

10 Aug 2010 Fine the number

A number when multiplied by 10 becomes 5 times the number obtained by adding 10 in the number. The number is?

OPtion

1) 11
2) 10
3) 12
4) 15
5) 17
6) 20
7) 25
8) 30
9) 16
10) 8

Solution

x.10 = 5.(10+x)
x.10 = 50 + 5x
5x = 50
X = 10

Correct Option: 2 Best Solution (18)

09 Aug 2010 Find the contribution?

The profit of a business is divided between A and B in the ratio 5:4. If contributions of A and B are
for 5 and 8 years respectively, and amount contributed by A is 8 lacs, then contribution by B in lacs is

OPtion

1) 8
2) 5
3) 6
4) 7
5) 4
6) 9
7) 5.5
8) 4.5
9) 3.5
10) 6.5

Solution

Amount (in lacs) * Time for A = 8*5 = 40
Amount (in lacs) * Time for B = x*8 = 8x
Now according to the given condition (40/8x) = 5/4
=> x = 4

Correct Option: 5 Best Solution (7)

06 Aug 2010 Integers

Sum of three positive integers is 9. Minimum value of the sum of squares of all the three numbers is?

OPtion

1) 33
2) 41
3) 35
4) 29
5) 51
6) 27
7) 26
8) 24
9) 21
10) 19

Solution

Minimum value of sum of squares is obtained only if all the three numbers are equal.

Correct Option: 6 Best Solution (6)