M4maths Previous Puzzles

29 May 2019 Probability

The probability that a girl student gets scholarship is 0.4 and that of a boy is 0.6, then probability that at least one gets the
scholarship is:

OPtion

1) 0.26
2) 0.30
3) 0.66
4) 0.24
5) 0.72
6) 0.74
7) 0.75
8) 0.76
9) 0.70
10) None of these

Solution

Probability that girl student gets scholarship is = 0.4
Probability that boys student gets scholarship is = 0.6
Hence, Probability that girl don't get scholarship = 1-0.4 = 0.6
Probability that boy don't get scholarship = 1-0.6 = 0.4

probability that at-least one gets scholarship is = 1- (no one selected)
1 -(0.6*0.4) = 0.76

Correct Option: 8 Best Solution (3)

28 May 2019 Series

What is the next term of following series:
43, 47, 53, 59, 61, 67, 71,

OPtion

1) 79
2) 78
3) 80
4) 72
5) 75
6) 76
7) 73
8) 77
9) 74
10) None of these

Solution

Series is formed by prime number starting at 43 so next prime number is 73
Option 7)

Correct Option: 7 Best Solution (3)

27 May 2019 Simple & Compound Interest

The absolute difference between simple and compound interests compounded annually on 20000 for 2 years at 5% per annum is :

OPtion

1) 100
2) 150
3) 200
4) 050
5) 300
6) 350
7) 125
8) 175
9) 225
10) None of these

Solution

SI = PRT/100 = 2000*5*2/100 = 2000
CI = P (1 + r/100)^t - P = 20000 (1+5/100)^2 - 20000 = 2050

Difference is 2050 - 2000 = 50

Correct Option: 4 Best Solution (5)

24 May 2019 Percentage

If an athlete's weight decreases from 180 pounds to 175.5 pounds, what is
the percent decrease?

OPtion

1) 2.4%
2) 2.7%
3) 2.5%
4) 2.0%
5) 2.6%
6) 2.8%
7) 2.9%
8) 2.1%
9) 3.0%
10) None of these

Solution

Percent Decrease = (180-175.5)*100/180 = 2.5%

Correct Option: 3 Best Solution (5)

23 May 2019 Distance Traveled

Two trains start at the same time from Gwalior and Delhi and proceed towards each other at 16 kmph and 24 kmph. respectively. when they meet it is found that one train has traveled 72 km more than the other the distance between the two stations is

OPtion

1) 340
2) 360
3) 248
4) 444
5) 334
6) 434
7) 480
8) 350
9) 380
10) None of these

Solution

let, t be the time when the trains meet each other.
so, 24t - 16t = 72
=> 8t = 72
=> t = 9
so, the distance between the two stations = 24t + 16t
= 40t
= 40*9
= 360 Km . (ans)

Correct Option: 2 Best Solution (0)

22 May 2019 Election

In an election a candidate who gets 63% of the votes is elected by a majority of 11,700 votes. What is the total number of votes polled ?

OPtion

1) 45300
2) 45200
3) 45400
4) 45080
5) 43000
6) 44000
7) 46600
8) 45000
9) 48080
10) None of these

Solution

Let the total number of votes polled be x.

Then, votes polled by other candidate = (100 - 63)% of x = 37% of x.

63% of x - 37% of x = 11,700
=> 27% of x = 11,700
=> x = 45000

Correct Option: 8 Best Solution (7)

21 May 2019 Profit & Loss

If by selling 105 balloons, the cost price of 120 balloons is realized. The gain % is?

OPtion

1) 18.49%
2) 12.71%
3) 15.02%
4) 14.29%
5) 15.40%
6) 14.80%
7) 16.02%
8) 17.08%
9) 19.10%
10) None of these

Solution

Let the cost pice of one balloon be Rs. 1

Cost Price of 110 Balloons = 110 Rs.
Selling price of 110 Balloons = Cost price of 120 Balloons = 120

Profit % = (120-105)*100/105 = 1500/105 = 14.29%

Correct Option: 4 Best Solution (4)

20 May 2019 Profit & Loss

Robert buys an old scooter from scrap for Rs. 4700 and spends Rs. 4000 on its repairs. If he sells the scooter for Rs. 21750, his gain percent is:

OPtion

1) 200%
2) 15%
3) 50%
4) 400%
5) 300%
6) 1.5%
7) 150%
8) 250%
9) 130%
10) None of these

Solution

Cost price for Robert including repairs = 4700 + 4000 = 8700

Profit = 21750 - 8700 = 13050
Profit % = (13050/8700)*100 = 150%

Correct Option: 7 Best Solution (5)

17 May 2019 Percentage

In last assembly elections for Delhi state, party A, B AND C fought against each other and got 28, 45 and 21 percent of total votes respectively. The remaining percent of votes went to others. For 2019 assembly election, party A urges party C to have an alliance so that they can beat party B.

Below facts hold good for 2019 election:
1. There is a 2% increase in vote percent of party B when compared to its own vote percent of 2014. Note: This 2% increase is only in comparison to Party B's vote percentage of 2014 and not on overall.
2. If Party A and C are forming an alliance then party A will loose 20% of its own vote percentage from what it has got in 2014, this vote percentage will go to others
3. Party's C vote share will remain same as 2014 with or without alliance with party A
4. Also, given that the number of voters in 2014 and 2019 are same.

Assuming an alliance between party A and C is formed, what is the vote percent difference between the party B and the alliance formed by A & C?

OPtion

1) 2.2%
2) 2.3%
3) 2.4%
4) 2.6%
5) 2.5%
6) 2.7%
7) 2.8%
8) 2.9%
9) 3.0%
10) None of these

Solution

Vote Percent of Party B in 2019 = 1.02*45 = 45.9
Vote Percent of Party A in 2019 = 0.8*28 = 22.4
Vote Percent of Party C in 2019 = 21

Total vote percent of alliance A+C = 43.4%

Winning party is B and margin is = 45.9 - 43.4 = 2.5%

Correct Option: 5 Best Solution (3)

16 May 2019 Simple Interest

Gappu's great grandfather did a fixed deposit of Rs 50,000/- at the simple interest rate of 10% in 1949, grand mother also did a fixed deposit of 5,00,000/- at the simple interest rate of 8% in 1974 and father did a fixed deposit of 500,000,000/- at the simple interest rate of 7% in 1989.
All these fixed deposits are maturing in 2019. How much amount would Gappu get in 2019?
Assume that Gappu is the sole owner for these deposits made by his family ancestors. Also, assume that once invested fixed deposit's interest rate continues to be fixed at the initial rate throughout the investment tenure.

OPtion

1) 1551700000
2) 1553700000
3) 1554700000
4) 1552100000
5) 1555700000
6) 1556700000
7) 1552700000
8) 1558700000
9) 1559700000
10) None of these

Solution

Amount of great grandfather's investment in 2019 = 50,000 + (50,000*10*70)/100 = 4,00,000
Amount of grand mother's investment in 2019 = 5,00,000 + (5,00,000*8*45)/100 = 23,00,000
Amount of father's investment in 2019 = 500,000,000 + (500,000,000*7*30)/100 = 15500,00,000

In 2019, Gappu would get = 4,00,000 + 23,00,000 + 15500,00,000 = 1552700000

Correct Option: 7 Best Solution (3)