M4maths Previous Puzzles

28 Mar 2013 circle

The perimeters of two semicircles are in the ratio 2:3. The ratio of their areas are..

OPtion

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

Solution

solve A1/A2 = (P1/P2)^2 = 4:9

Correct Option: 6 Best Solution (20)

27 Mar 2013 problem

If x percent of x is equal to y/5 and the square difference of x and 10 is equal to square of y. value of y is

OPtion

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

Solution

x*x/100=y/5 (i)
x^2-10^2=y^2 (ii)
solve the equations
then y = 10 (with both sign)
option (5)

Correct Option: 5 Best Solution (0)

26 Mar 2013 polynomials

If x=p,y=q,z=r, Marks(+,-,*,/) is equal to (*,+,/,-) respectively and x=1,q=2,z=3
then (x*q)+(y-z)/p

OPtion

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

Solution

(1/2)*(2+3)-1 = ((1/2)*5)-1 = (5/2)-1 = 1.5 = 3/2

Correct Option: 5 Best Solution (0)

25 Mar 2013 sequence

What is the next no of the following sequence
10, 40, 270, 2560,.........

OPtion

1) 1250
2) 2250
3) 6250
4) 12500
5) 31250
6) 62500
7) 125000
8) 225000
9) 625000
10) None of these

Solution

10 = 1^1*10
40 = 2^2*10
270 = 3^3*10
2560 = 4^4*10
5^5*10 = 31250

Correct Option: 5 Best Solution (11)

23 Mar 2013 AP

Two AP have the same common difference. The difference between their 100th terms is 111222333. The difference between their 10000th term will be...

OPtion

1) 111122223333
2) 112233
3) 111222333
4) 222111333
5) 333222111
6) 123123123
7) 321321321
8) 231231231
9) 0
10) None of these

Solution

let first AP first terms be x and difference d
and let second AP first terms be y and difference d (given common difference same)
By the given condition
first AP (Ist)t100 = x + 99d (i)
second AP (IInd)t100 = y + 99d (ii)
solve (i) and (ii)
therefore x-y = 111222333 (iii)
then
(Ist) t10000 = x + 9999d (iv)
(IInd)t10000 = y + 9999d (v)
(Ist)t10000 + (IInd)t10000 = x - y
= 111222333 (By (iii) equation
same (option 3)

Correct Option: 3 Best Solution (1)

22 Mar 2013 parallelogram

A obtuse angle of a parallelogram is twice its acute angle. Each angle of the parallelogram will be...

OPtion

1) 30, 150, 30, 150
2) 30, 60, 30, 60
3) 25, 155, 25, 155
4) 50, 100, 50, 100
5) 120, 240, 120, 240
6) 30, 60, 30 60
7) 60, 120, 60, 120
8) 75, 150, 75, 150
9) 45, 90, 45, 90
10) None of these

Solution

in a parallelogram opposite side are parallel
there for sum of interior angle is 180
and sum of all angle 360
by the given condition
x+2x= 180 (let acute angle be x)
3x=180
x=60
therefore 60, 120, 60, 120
option no 7

Correct Option: 7 Best Solution (0)

20 Mar 2013 age problem

The sum of ages of A and B is 49 years. A says to B "I am twice as old as you were when I was as old as you are". What is A and B present age.

OPtion

1) A=28,B=21
2) A=27,B=22
3) A=29,B=20
4) A=30,B=19
5) A=40,B=9
6) A=39,B=10
7) A=38,B=11
8) A=36,B=13
9) A=35,B=14
10) None of these

Solution

A+B=49 (i)
(A-B) year before
A = 2(B-(A-B))
A = 2(B-A+B)
A=4B-2A
3A=4B (ii)
solve (i) and (ii) equation
A=28,B=21
option 1

Correct Option: 1 Best Solution (0)

19 Mar 2013 Problem

In an examination paper one mark is awarded for every correct answer while 1/4 marks are deducted for wrong answer. A student answered 120 questions and got 90 marks how may questions did he answer correctly.

OPtion

1) 24
2) 36
3) 40
4) 72
5) 80
6) 90
7) 96
8) 56
9) 64
10) None of these

Solution

let correct answer be x
wrong answer be y
by the given condition
x + y = 120 (i)
x(1) - y(1/4) = 90 (ii)
solve equations
x = 96
y = 24
correct answer 96
option 7

Correct Option: 7 Best Solution (0)

18 Mar 2013 sequence

What is the next no. of the following sequence
3, 6, 29, 258, ........

OPtion

1) 4096
2) 3844
3) 3600
4) 3364
5) 3127
6) 2916
7) 2166
8) 1298
9) 729
10) None of these

Solution

2+1^1 = 3
2+2^2 = 6
2+3^3 = 29
2+4^4 = 258
2+5^5 = 3127

Correct Option: 5 Best Solution (12)

15 Mar 2013 word problem

At present fathers age is sum of mothers and sons age. If 5 years ago mothers age was 9 times sons age then fathers age at that time was
(given that the age of father at the time of birth of child was 32)

OPtion

1) 29
2) 30
3) 31
4) 32
5) 33
6) 34
7) 35
8) 36
9) 37
10)none of these

Solution

according to given conditions
f=m+s
m-5=9(s-5)
f-s=32
solve f
f-5 will be answer

Correct Option: 7 Best Solution (11)