M4maths Previous Puzzles

12 Jun 2019 Time and Work

It takes Mr. Rahul y hours to complete an assignment. After 3 hours, he was called away. What fractional part of the assignment was left incomplete?

OPtion

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

Solution

for 1 hour he will do 1/y work...
for 2 hour he will do 2/y work...
So for 3 hours he will do 3/y work...
remaining work= 1-(3/y)
therefore answer is (y-3)/y.

Correct Option: 6 Best Solution (4)

11 Jun 2019 Odd man out

Find the odd man out from the following series:
2, 3, 5, 7, 11, 13, 17, 19, 21, 23,

OPtion

1) 2
2) 3
3) 5
4) 7
5) 11
6) 13
7) 17
8) 19
9) 21
10) 23

Solution

Except 21 rest all prime numbers

Correct Option: 9 Best Solution (8)

10 Jun 2019 Average

The price of a product was reduced by 35% last year. During this year by what percentage should it be increased to bring it back to the original price of last year?

OPtion

1) 52.67
2) 42.17
3) 53.85
4) 51.06
5) 52.58
6) 12.05
7) 53.36
8) 53.76
9) 53.80
10) None of these

Solution

If initial price is Rs 100 and reduced price is Rs 65.

Then to make it 100 again, price should increase by 100*35/65= 53.85

Correct Option: 3 Best Solution (6)

07 Jun 2019 Distance Traveled

A tempo, while travelling at 70 kmph, uses 40% more petrol than it uses while travelling at 50 kmph for travelling a certain distance. Using one litre of petrol, it can travel 19.6 km at 50 kmph. How far can the tempo travel (in KMs) on 10 litres of petrol at a speed of 70 kmph?

OPtion

1) 140
2) 240
3) 248
4) 560
5) 260
6) 270
7) 280
8) 300
9) 180
10) None of these

Solution

At 50 kmph , one km distance uses 1/19.6 litre petrol.
At 70kmph, one km distance uses 1.4/19.6 litre petrol
Distance traveled with 10 ltrs @ 70kmph = 10*19.6/1.4= 140 kms.

Correct Option: 1 Best Solution (7)

06 Jun 2019 Factors

How many factors of 1230356435 are odd number?

OPtion

1) 12
2) 80
3) 16
4) 60
5) 30
6) 14
7) 20
8) 15
9) 24
10) None of these

Solution

1230356435 = 5^1 * 7^5 *11^4

Any factor of this number should be of the form 5^a * 7^b * 11^c.

For the factor to be a odd number a,b,c can take any value as product of 3 odd numbers would always be odd

a can take values 0, 1
b can take values 0, 1, 2, 3, 4, 5
and c can take values 0, 1, 2, 3, 4

Total number of odd factor = 2 * 6 * 5 = 60

Correct Option: 4 Best Solution (3)

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 (8)

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)