M4maths Previous Puzzles

05 Jun 2019 AP

If 7 times the 7th term of an AP is equal to 11 times its 11th term, What is the value of 18th term ?

OPtion

1) 36
2) 56
3) 32
4) 64
5) 85
6) 80
7) 88
8) 0
9) 27
10) None of these

Solution

7a+42d=11a+110d
68d=-4a
a=-17d
now 18th term...a+17d as nth term is a+(n-1)d
a+17d=-17d+17d=0
hence answer is 0

Correct Option: 8 Best Solution (3)

04 Jun 2019 LCM

Two numbers are in the ratio 3:7. If their L.C.M. is 189. what is sum of the numbers?

OPtion

1) 70
2) 80
3) 60
4) 81
5) 71
6) 90
7) 89
8) 88
9) 99
10) None of these

Solution

Let the numbers be 3x and 7x

LCM of 3x and 7x is 21x
So as per question 21x = 189

=> x= 9
So 3x = 3*9 = 27 and 7x = 7*9 =63


Sum of the numbers = 27+63 = 90

Correct Option: 6 Best Solution (2)

03 Jun 2019 Average

In their first world cup match against New Zealand, Sri Lankan batsmen scored below runs:
4
52
29
0
4
0
1
27
0
7
1
What is their average score?

OPtion

1) 12.67
2) 12.17
3) 11.67
4) 11.06
5) 12.58
6) 12.05
7) 11.36
8) 12.76
9) 11.30
10) None of these

Solution

Sum of Scores: 125
Average = 125/11 = 11.36

Correct Option: 7 Best Solution (7)

31 May 2019 Profit & Loss

Pappu purchases 2 gadgets for Rs. 1120. He sells one at 15% profit and the other at 10% loss. He neither gains nor loses. The difference in the cost prices of 2 gadgets is?

OPtion

1) 244
2) 240
3) 248
4) 222
5) 260
6) 224
7) 284
8) 264
9) 268
10) None of these

Solution

Let the price of the 2 gadgets be x and y.
Thus x+y=1120
Now let x be sold at 15% profit and y be sold at 10% loss.
Thus 115x+90y=112000
Or 115x - 90(1120-x) = 112000
Or 115x - 90x + 100800 = 112000
Or 25x = 11200
Or x = 448
Thus y = 672

Difference = 672-448 = 224

Correct Option: 6 Best Solution (7)

30 May 2019 Numbers

Sum of the 7 consecutive integers is 1617. Find the sum of prime numbers in that sequence

OPtion

1) 440
2) 380
3) 520
4) 560
5) 550
6) 470
7) 480
8) 360
9) 460
10) None of these

Solution

Let the numbers be x, x+1, x+2, x+3, x+4, x+5, x+6
Since their sum equals 1617, we have-
x+(x+1)+(x+2)+(x+3)+(x+4)+(x+5)+(x+6)=1617
7x+21=1617
7x=1596
x=228

Hence the numbers are: 228,229,230,231,234,235,236
Prime Numbers: 229, 233

Sum of prime numbers = 462

Correct Option: 10 Best Solution (0)

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 (2)

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 (2)

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 (4)

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)