M4maths Previous Puzzles

22 Mar 2019 Probability

A woman who goes to work long before sunrise every morning gets dressed in the dark. In her socks drawer she has 9 black and 12 blue socks. What is the probability that her first pick was a black sock, but her second pick was a blue socks?

OPtion

1) 17/70
2) 8/35
3) 9/35
4) 19/70
5) 23/70
6) 7/36
7) 9/37
8) 6/35
9) 11/45
10) None of these

Solution

Probability= (9/21)*(12/20) = (3/7)*(3/5) = 9/35

Correct Option: 3 Best Solution (0)

21 Mar 2019 Calendar

Day after tomorrow is my birthday, on the same day next week falls 'Holi'. Today is Wednesday. What will be the day after 'Holi'?

OPtion

1) Monday
2) Tuesday
3) Wednesday
4) Thursday
5) Friday or Saturday
6) Saturday or Sunday
7) Sunday
8) Friday
9) Saturday
10) None of these

Solution

Today is Wednesday
Tomorrow would be Thursday
Day after tomorrow would be Friday
So Holi is on Friday and the day after holi would be Saturday

Correct Option: 9 Best Solution (4)

20 Mar 2019 Investment

In a business Nirav invests Rs.72000. After 6 months his uncle invests Rs.54,000. After one year they got a profit of Rs.22,000. Then uncle gets his share as

OPtion

1) 12000
2) 5000
3) 16000
4) 6000
5) 14000
6) 7000
7) 15000
8) 8000
9) 4000
10) None of these

Solution

Nirav=72,000(12months)
uncle=(54000)(6months)
72000*12 : 54000*6
4*2 : 3*1 = 8:3
uncle share= (3/11)(22000)=6000

Correct Option: 4 Best Solution (0)

19 Mar 2019 Rank

Pappu ranks twenty seventh in a class of fourty four. What is his rank from the last?

OPtion

1) 12
2) 13
3) 17
4) 18
5) 14
6) 19
7) 16
8) 20
9) 15
10) None of these

Solution

Rank from last: 44-27+1=15 = 18

Correct Option: 4 Best Solution (5)

18 Mar 2019 Ages

The total ages of X and Y is 23 years more than the total ages of Y and Z. How many years is Z younger than X?

OPtion

1) 12
2) 13
3) 15
4) 14
5) 16
6) 23
7) 21
8) 22
9) 24
10) None of these

Solution

x + y - (y+z) = 23
=> x - z = 23
Z is 23 yrs younger than X.

Correct Option: 6 Best Solution (0)

15 Mar 2019 Fraction

There are total 45 people. 21 speaks French and 17 speaks Spanish 9 do not speak any language. Which part of total people speaks both languages.

OPtion

1) 5/1
2) 4/1
3) 6/1
4) 3/1
5) 5/45
6) 4/45
7) 1/15
8) 2/15
9) 2/45
10) None of these

Solution

If x no of people speak both languages then

45 = 21 + 17 - x + 9
=> x=2
so part of total people speaks both languages = 2/45

Correct Option: 9 Best Solution (11)

14 Mar 2019 Profit & Loss

An article when sold at a gain of 5% yields Rs. 56 more than when sold at a loss of 15%. The cost price of the article is:

OPtion

1) 150
2) 200
3) 180
4) 240
5) 280
6) 320
7) 260
8) 270
9) 300
10) None of these

Solution

Let CP =100%
Also by formula SP%=CP%-loss%
SP%=CP%+Profit%
Thus we have SP%=105%..in profit
SP%=85%...in loss
Thus. (105-85)%=20%

So diff is 20 when CP was 100
For 56, CP = (100/20)*56 = 280

Correct Option: 5 Best Solution (0)

13 Mar 2019 Width of River

From a point on a bridge across a river, the angles of depression of the banks on opposite sides of the river are 60° and 45° respectively. If the bridge is at a height of 9 meter from the banks then find the width of the river? Assume both the banks are at same ground level.

OPtion

1) 14.02 m
2) 14.11 m
3) 14.20 m
4) 14.40 m
5) 14.73 m
6) 14.35 m
7) 14.05 m
8) 14.53 m
9) 14.63 m
10) None of these

Solution

Let A and B be the two sides of the river and C be the point on the bridge. D is a point on straight line between A and B such that CD = 9 meters

Width of the river would = AD+BD

In right angled triangle ACD,
tan 60° = CD/AD
=> √3 = 9/AD
=> AD = 9/√3 = 3√3

In right angled triangle BCD,
tan 45° = CD/BD
=> 1 = CD/BD
=> CD = BD = 9 meters

So the width of the river is AD+BD = 9+3√3 = ~14.20 meters

Correct Option: 3 Best Solution (5)

12 Mar 2019 Word Done

A certain number of men can finish a piece of work in 30 days. If however there were 15 men less it will take 30 days more for the work to be finished. How many men were there originally?

OPtion

1) 15
2) 20
3) 18
4) 24
5) 21
6) 25
7) 26
8) 27
9) 30
10) None of these

Solution

A certain number of men can finish a piece of work in 30 days. If however there were 15 men less it will take 30 days more for the work to be finished.
So the no. of days are doubled (from 30 to 60) , it means no. is men is reduced to half.
so earlier, there were 15*2= 30 men.

Correct Option: 9 Best Solution (0)

12 Mar 2019 Ratio

Initially two cups of same volume are present with milk filled upto 2/7th and 3/7th of their volumes. Water is then filled in both the cups (completely). Then two mixtures are mixed. Find the ratio of water to milk in the mixture?

OPtion

1) 8:5
2) 7:4
3) 5:9
4) 9:5
5) 11:3
6) 5:8
7) 13:9
8) 7:2
9) 5:7
10) None of these

Solution

Let the cups volume be x.
here we assume that water fills both volumes completely
after mixing , total milk is -> 2/7x + 3/7x = 5/7x
after mixing , total water is -> 5/7x + 4/7x = 9/7x
therefore water to milk ratio is (9/7)/(5/7) = 9:5

Correct Option: 4 Best Solution (0)