M4maths Previous Puzzles

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)

11 Mar 2019 Code Written

A programmer has the capability of thinking 70 lines of code in six minutes and can type 70 lines of code in 12 minutes. He takes a break for six minutes after every 12 minutes. How many lines of codes will he complete writing in 72 minutes?
Assume that he always needs to think before writing any code?

OPtion

1) 250
2) 165
3) 180
4) 150
5) 135
6) 175
7) 155
8) 200
9) 210
10) None of these

Solution

6-think
6-type
6-break
6-type
6-think
6-break
6-type
6-type
6-break
6-think
6-type
6-break


So five times for 6 minutes he types/writes code, total minutes he spends typing the code = 6*5 = 30 minutes
In 12 Minutes he can type 70 lines of code
In 30 minutes he types (70/12)*30 = 175 lines

Correct Option: 6 Best Solution (3)

08 Mar 2019 Distance Traveled

A tempo, while travelling at 75 kmph, uses 25% more petrol than it uses while travelling at 50 kmph for travelling a certain distance. Using one liter of petrol, it can travel 22.5 km at 50 kmph. How far can the tempo travel on 15 liters of petrol at a speed of 75 kmph?

OPtion

1) 180
2) 220
3) 240
4) 260
5) 270
6) 280
7) 300
8) 320
9) 330
10) None of these

Solution

At 50kmph
22.5 KM is traveled with 1 liter petrol
1 KM is traveled with 1/22.5 liter

At 75 KMPH
It uses 25% extra petrol
So 1 KM is traveled with 1.25*1/22.5 liter

Distance traveled with 15 liters @ 75 KMPH = 15* 22.5/1.25 = 270 KM

Correct Option: 5 Best Solution (0)

07 Mar 2019 Envelopes Used

An Office used three types of envelopes: small,medium and large. They used 160 small envelopes. The no.of Medium envelopes used was 5 times the no. of small envelopes plus 5/20 of the total number of envelopes. The no. of large envelopes was equal to the no. of small envelopes plus 5/20 of the no. of medium envelope. Altogether, How many envelope did they use?

OPtion

1) 1600
2) 2280
3) 3280
4) 2640
5) 1540
6) 1280
7) 1640
8) 1840
9) 1920
10) None of these

Solution

Let the total no. of envelopes be x

No. of small envelopes = 160
No. of medium envelopes =5*160+5/20*x = 800+5/20*x
No. of large envelopes = 160 +5/20(800+5/20*x) = 360 + 25/400*x

Sum of small, medium and large envelopes = x

160 + 800 + 5/20*x + 360 + 25/400*x = x
1320 + 125/400*x = x
1320*x + 5/16 = x
=> 11/16 x = 1320
x = 1920

Correct Option: 9 Best Solution (0)