M4maths Previous Puzzles

13 May 2010 P and C

We have to make numbers by using the digits 1,4,9,5,5,2,5.
A numbers are less than 2000000, B numbers are between 2000000 and 4000000,
C numbers are between 4000000 and 6000000,
D numbers are between 6000000 and 8000000
and E numbers are greater than 8000000, then
4A + 3B - 2C + 5D + 3E =

OPtion

1) 0
2) 300
3) 120
4) 480
5) 240
6) 360
7) 720
8) 600
9) -120
10) -360

Solution

Numbers less than 2000000 will start from 1 only
Hence A = (1*6*5*4*3*2*1)/ (3*2*1) = 120
Numbers between 2000000 and 4000000 will start from 2 only
Hence B = (1*6*5*4*3*2*1)/ (3*2*1) = 120
Numbers between 4000000 and 6000000 will start from 4 and 5
Hence C = (4*6*5*4*3*2*1)/ (3*2*1) = 480
There is no possibility for a number to be between 6000000 and 8000000.
Hence D = 0
Numbers greater than 8000000 will start from 9 only
Hence E = (1*6*5*4*3*2*1)/ (3*2*1) = 120
Thus 4A + 3B - 2C + 5D + 3E
= 4*120 + 3*120 - 2*480 + 5*0 + 3*120
= 240

Correct Option: 5 Best Solution (5)

12 May 2010 Train Length?

A train crosses a platform of 120 m. length in 10 sec. and a pole in 6 sec. What will be the length of the train?

OPtion

1) 100
2) 120
3) 90
4) 150
5) 160
6) 110
7) 180
8) 80
9) 95
10) 240

Solution

Let the length of the train is x m.
According to the given conditions
v = (120 + x)/10 (i) and v = x/6 (ii)
On comparing (i) and (ii)
(120 + x)/10 = x/6
=> 6 (120 + x) = 10 x
=> 720 + 6 x = 10 x
=> 720 = 4 x
=> 180 = x

Correct Option: 7 Best Solution (18)

11 May 2010 Stations distance ?

Distances between stations X and Y, Y and Z, Z and X are 100 km. Angle between the lines made by joining X and Y, Y and Z is

OPtion

1) 50 degree
2) 45 degree
3) 30 degree
4) 25 degree
5) 60 degree
6) 100 degree
7) 120 degree
8) 10 degree
9) 20 degree
10) 150 degree

Solution

An equilateral triangle is formed by joining stations X, Y and Z. Hence required angle is 60 degree.

Correct Option: 5 Best Solution (23)

10 May 2010 Mixture amount ?

A mixture contains 3 components A, B, C in the ratio 7:8:9. If amount of component C is 99 Kg. What will be
the total amount of the mixture?

OPtion

1) 77 Kg
2) 88 Kg
3) 264 Kg
4) 165 Kg
5) 364 Kg
6) 292 Kg
7) 187 Kg
8) 176 Kg
9) 24 Kg
460 Kg

Solution

[Amount of (C)/9] = [Amount of (A + B + C)/24]
99/9 = x/24
11*24 = x
x = 264

Correct Option: 3 Best Solution (16)

07 May 2010 max area of rectangle?

What will be the max area of a rectangle if its parameter is 36 cm?

OPtion

1) 64
2) 72
3) 81
4) 100
5) 110
6) 80
7) 77
8) 72
9) 24
10) 65

Solution

All square are rectangle. so for the max area all side will be 9 cm
and area will become 9*9 = 81 cm^2

Correct Option: 3 Best Solution (7)

06 May 2010 How many letter are possible?

How many 4 digit words are possible by using English alphabet a to z with condition
one alphabet is not allow more than twice consecutively ex- "aaab", "cccc" not allowed

OPtion

1) 456976
2) 455650
3) 456345
4) 331776
5) 358800
6) 234545
7) 453444
8) 355650
9) 546784
10) 1360

Solution

Total possible 4 digit character are = 26*26*26*26 = 456976
and 3 and 4 consecutive possible letters are = (26*2-1)*26 = 1326
so possible letters are 456976 - 1326 = 455650

Correct Option: 2 Best Solution (3)

05 May 2010 what will be the next number

what will be the next number
12, 14, 116, 1136, 11936, ?

OPtion

1) 11436
2) 43567
3) 1389
4) 1181936
5) 11836
6) 94368
7) 43681
8) 1141636
9) 22987
10) 1198136

Solution

next number is square of every digit
11936

1^2 1^2 9^2 3^2 6^2
1 1 81 9 36

Correct Option: 4 Best Solution (10)

04 May 2010 discount offer

What is the difference in discount amount of two product?
both product is of 200 RS.
In one product there is a discount offer of 50%.
and in another there is a discount offer of 30%+20%.

OPtion

1) 0
2) 1
3) 5
4) 6
5) 8
6) 12
7) 16
8) 20
9) 24
10) 30

Solution

total discount in 50% offer is = 100
and in 30% +20% is = 60 + 28 = 88
difference = 12 rs

Correct Option: 6 Best Solution (17)

03 May 2010 find the next number

what will be the next number of the series?
3,3,5,4,4,?

OPtion

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

Solution

One 3
two 3
three 5
four 4
five 4
six 3

Correct Option: 3 Best Solution (8)

30 Apr 2010 NO two girl sit together

Number of methods of arranging 4 boys and 4 girls in a round table such that no 2 girls sit together is ?

OPtion

1) 36
2) 576
3) 72
4) 40320
5) 144
6) 24
7) 6
8) 5040
9) 8
10) 4

Solution

Method- First we have to arrange 4 boys after than 4 girls according to the given condition
Number of methods of arranging 4 boys in a round table is 3*2*1 = 6
Number of methods of arranging 4 girls between boys is 4*3*2*1 = 24
Hence total no. of methods is 6*24 = 144

Correct Option: 5 Best Solution (4)