M4maths Previous Puzzles

15 Aug 2018 Simple Interest

What would Rs 1947 amount to when invested for a period of 70 years where rate of simple interest is 6%?

OPtion

1) 8177.4
2) 10126.4
3) 10142.4
4) 8117.4
5) 10124.4
6) 10129.4
7) 8171.4
8) 10140.4
9) 10118.4
10) None of these

Solution

SI = PRT/100 = 1947*70*6/100 = 8171.4

A = SI+P =10124.4

Correct Option: 5 Best Solution (1)

14 Aug 2018 Probability

An alphanumeric character is randomly picked from below quote by Lala Lajpat Rai
"The shots that hit me are the last nails to the coffin of the British rule in India."

What is the probability that picked character is one of the following letters I or N or D or A?
Note: Alphanumeric character means alphabet or number. Space and other characters should be ignored.

OPtion

1) 18/60
2) 18/63
3) 17/65
4) 18/65
5) 17/66
6) 18/67
7) 3/11
8) 19/67
9) 18/64
10) None of these

Solution

Sentence = "The shots that hit me are the last nails to the coffin of the British rule in India."


Total number of alphanumeric character in the sentence = 16
Total Number of I = 8, N = 4 or D= 1 or A=5
Total = 18

Probability = (18)/66 = 3/11
Option 7)

Correct Option: 7 Best Solution (0)

13 Aug 2018 Discount

The marked price of a shirt is Rs.1947. A shopkeeper offers three successive discount of 8%, 15% and 30%. How much will you have to pay, finally?

OPtion

1) 1005.79
2) 965.79
3) 985.79
4) 1065.79
5) 995.79
6) 996.79
7) 999.79
8) 1001.79
9) 1000.79
10) None of these

Solution

Price after 1st Discount = 1947*92/100 = 1791.24

Price after 2nd Discount = 1791.24*85/100 = 1522.554

Price after 3rd discount = 1522.554*70/100 =1065.79


Hence Option 4)

Correct Option: 4 Best Solution (3)

10 Aug 2018 Compound Interest

What is the rate of compound interest (compounded annually) when a sum of Rupees 2018 amounts to 4356.711 in 10 years ?

OPtion

1) 6.25
2) 6.50
3) 7.25
4) 7.75
5) 6.75
6) 7.00
7) 7.50
8) 6.00
9) 8.00
10)None of these

Solution

CI+P = P [(1+r)^T] = 2018 [(1+R/100)^10 ]

=> 4356.711 = 2018 [(1+R/100)^10]

=> Solving we get R = 8
Option 9)

Correct Option: 9 Best Solution (1)

09 Aug 2018 Statistics

Run Scored by Murali, Shikhar, Rahul, Virat, Ajinkya, Hardik, Dinesh, Ashwin, Shami, Ishant and Umesh in 1st Test Match are: 26 39 17 200 17 53 20 23 2 16 and 1 respectively.

What is the population standard deviation of their marks?

OPtion

1) 53.35
2) 53.45
3) 53.59
4) 53.99
5) 53.91
6) 53.25
7) 53.81
8) 53.96
9) 53.19
10)None of these

Solution

Mean of 10 marks = 414/11 = 37.63
Sum of squared difference from mean for each number = (26-37.63)^2 + (39-37.63)^2 + ......+ (1-37.63)^2 = 31192.55

Average of Squared difference (Variance) = 31192.55/11 = 2835.686
Population Standard Deviation = Square root of variance = 2835.686^1/2 = ~53.25

Option 6)

Correct Option: 6 Best Solution (7)

08 Aug 2018 Probability

2 dices are rolled. What is the probability of getting the total score as a prime number?

OPtion

1) 4/9
2) 7/18
3) 13/36
4) 1/3
5) 1/2
6) 1/4
7) 5/18
8) 11/36
9) 17/36
10) None of these

Solution

Total number of possible outcomes = 6*6 =36

Number of postive outcomes where sum total is prime = { (1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4,3),(5, 2), (5, 6), (6, 1), (6, 5) }
Count of such outcomes = 15

Probability =15/36 = 5/12

Option 10)

Correct Option: 10 Best Solution (7)

07 Aug 2018 Simple Interest

At what simple interest rate percent per annum will a sum of money triple in 11 years.

OPtion

1) 17.50
2) 18.00
3) 17.33
4) 18.50
5) 17.25
6) 18.18
7) 18.75
8) 17.75
9) 18.33
10) None of these

Solution

SI = PRT/100

SI = 2P

So 2P = P*R*11/100
= R= 200/11 = 18.18
Option 6)

Correct Option: 6 Best Solution (5)

06 Aug 2018 Probability

It is given that correct answer to our today's question is not an even numbered option out of given 10 options. A user who knows this makes a random guess out of non even options. What is the probability that his guess is right?

OPtion

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

Solution

Number of odd options/even options = 5
User randomly selects one option out of 1, 3, 5, 7, 9.So, probability that his guess is right = 1/5

Correct Option: 3 Best Solution (1)

03 Aug 2018 Profit and Loss

A vendor bought 450 toffees for 3150 rupees. How many toffees in 2821 rupees must he sell to gain 30%?

OPtion

1) 331
2) 310
3) 311
4) 321
5) 320
6) 300
7) 340
8) 325
9) 324
10)None of these

Solution

CP of 1 toffees = 3150/450 = Rs. 7
SP of 1 toffees for 30% profit = 7*1.3 = Rs. 9.1
So in 2730 Rupess number of toffees to be sold = 2821/9.1 = 310

Option 2)

Correct Option: 2 Best Solution (3)

02 Aug 2018 Compound Interest

What would be compound interest (compounded annually) on a sum of Rupees 2018 at the rate of 8% for a period of 2 years?

OPtion

1) 2353.80
2) 2358.05
3) 0335.80
4) 3210.41
5) 3320.41
6) 3300.41
7) 0392.41
8) 0282.41
9) 2297.41
10)None of these

Solution

CI = P [(1+r)^T -1] = 2018 [(1+8/100)^2 -1]
=> 2018 [1.08^2 -1 ] = 335.7952 = ~335.80
Option 3)

Correct Option: 3 Best Solution (5)