M4maths Previous Puzzles

04 May 2016 Coded language

If in coded language
50 = 66
60 = 97
70 = 110
80 = 74
Then
20 = ?

OPtion

1) 101
2) 106
3) 105
4) 104
5) 103
6) 102
7) 107
8) 108
9) 109
10)110

Solution

Codes are formed by the transformations given below
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

50 = FIFTY = F+I+F+T+Y = 6+9+6+20+25 = 66
Similarly for others.
Option 7)

Correct Option: 7 Best Solution (9)

03 May 2016 Find the number of ball

A bag contain 5 red balls and some blue balls. If the probability of drawing a blue ball from the bag is four time that of a red ball, then find the number of blue balls in the bag.

OPtion

1) 10
2) 12
3) 15
4) 20
5) 22
6) 25
7) 30
8) 35
9) 40
10)None of these

Solution

Number of red balls = 5
Let the number of blue balls = x
Therefore Total number of balls in the bag = (5+x)
According to the question
P(blue ball) = 4 P(red ball)
x/(5+x) = 4(5/(5+x))
x = 20
Option 4)

Correct Option: 4 Best Solution (11)

02 May 2016 Sequence

What is the next number of the following sequence
226, 251, 262, 287, .....

OPtion

1) 401
2) 417
3) 364
4) 389
5) 462
6) 434
7) 398
8) 407
9) 400
10)None of these

Solution

226
226+(2*2*6+1) = 226+(24+1) = 226+25 = 251
251+(2*5*1+1) = 251+(10+1) = 251+11 = 262
262+(2*6*2+1) = 262+(24+1) = 262+25 = 287
Similarly
287+(2*8*7+1) = 287+(112+1) = 287+113 = 400

Option 9)

Correct Option: 9 Best Solution (12)

29 Apr 2016 Total length of the silver wire

A brooch is made with silver wire in the form of a circle with diameter 35 mm. The wire is also used in making 5 diameters which divide the circle into 10 equal parts. Find the total length of the silver wire required.

OPtion

1) 185 cm
2) 38 cm
3) 285 mm
4) 174 mm
5) 196 mm
6) 58 cm
7) 84 cm
8) 265 mm
9) 325 mm
10)125 mm

Solution

Diameter of the circle = 35 mm
Therefore radius r = 35/2 mm
Therefore Total length of wire required = Length of wire required for making 5 diameter + Length of wire required for making the perimeter of circle
= 5 * 35 * 2*Pi*35/2 mm
= 175 + 22/7*35 mm
= 285 mm
Option 3)

Correct Option: 3 Best Solution (17)

28 Apr 2016 Probability

Sanjay and Tusar play a tennis match. It is knows that the probability of Sanjay winning the match is 0.62. What is the probability of Tusar winning the match?

OPtion

1) 0.62
2) 0.34
3) 0.64
4) 0.66
5) 0.36
6) 0.38
7) 0.68
8) 0.40
9) 0.72
10)0.28

Solution

Let us denote the event Sanjay wins the tennis match by S and the event, Tusar wins the tennis match by R.
Given that P(S) = 0.62 Now, the events S and R are complementary because only one event can happen at time i.e. not S means the event R and nor R means the event S
P(S) + P(R) = 1
P(R) = 1-0.62 = 0.38
Option 6)

Correct Option: 6 Best Solution (18)

27 Apr 2016 Area

Water in a canal, 30 dm wide and 12 dm deep is flowing with velocity of 10 km/hr. How much area will it irrigate in 30 minutes, if 8 cm of standing water is required for irrigation?

OPtion

1) 425000 m^2
2) 4.25 km^2
3) 0.4 km^2
4) 275000 m^2
5) 1.8 km^2
6) 225000 m^2
7) 235500 m^2
8) 4000000 m^2
9) 180000 m^2
10)40 k^2

Solution

Width of the canal = 30 dm = 300 cm = 3 m
Depth of the canal 12 cm = 120 cm = 1.2 m
It is given that the water is flowing with velocity 10 km/hr
Therefore Length of the water column formed is 1/2 hour = 5 km = 5000 m
Therefore volume of the water flowing in 1 hour
= Volume of the cuboid of length 5000 m, width 3 m and depth 1.2 m
=> Volume of the water in half hour = (5000*3*1.2) m^3 = 18000 m^3
Suppose x m^2 area is irrigated in 1/2 hour
x*8/100 = 18000
x = 1800000/8
x = 225000
Hence the canal irrigated 225000 m^2 area in 1/2 hours
Option 6)

Correct Option: 6 Best Solution (15)

26 Apr 2016 Find the number of coins

A bag contain 1-rupee, 50-paisa and 25-paisa coins in the ratio 5:6:7. If the total amount is Rs.780, find the number of coins of each kind.

OPtion

1) 200, 240, 280
2) 400, 480, 580
3) 400, 380, 560
4) 400, 440, 520
5) 480, 520, 640
6) 400, 580, 620
7) 480, 540, 580
8) 400, 480, 560
9) 200, 420, 560
10)None of these

Solution

Ratio of value of the coins 5/1 : 6/2 : 7/4 = 20:12:7
Value of 1 rupee coins = Rs.(780*20/39) = Rs.400
Value of 50-paise coins = Rs.(780*12/39) = Rs.240
Value of 20-paise coins = Rs.(780*7/39) = Rs.140
Therefore
Number of 1 Rupee coins = 400
Number of 50-paise coins = 240*2 = 480
Number of 25-paise coins = 140*4 = 560

Option 8)

Correct Option: 8 Best Solution (25)

25 Apr 2016 Sequence

What is the next number of the following sequence
67, 78, 89, 910, 1021, ......

OPtion

1) 1122
2) 2121
3) 1011
4) 1132
5) 2132
6) 2122
7) 2124
8) 2113
9) 1133
10)2123

Solution

67
(6+1)(7+1) = 78
(7+1)(8+1) = 89
(8+1)(9+1) = 910
(9+1)(1+1)(0+1) = 1021
Similarly
(1+1)(0+1)(2+1)(1+1) = 2132
Option 5)

Correct Option: 5 Best Solution (15)

22 Apr 2016 Member in the group

A group of students decided to collect as many paise from each member of the group as is the number of members. If the total collection amounts to Rs 22.09, the number of the members in the group is

OPtion

1) 36
2) 37
3) 47
4) 48
5) 43
6) 54
7) 68
8) 95
9) 107
10)None of these

Solution

Number of member = Sqrt2209 = 47
Option 3)

Correct Option: 3 Best Solution (27)

21 Apr 2016 Number

The ascending order of rational numbers
a) -7/10
b) 5/-8
c) 2/-3

OPtion

1) a b c
2) b c a
3) c a b
4) b a c
5) c b a
6) a c b

Solution

Solve by using decimal fraction

Option 6)

Correct Option: 6 Best Solution (28)