M4maths Previous Puzzles

28 Apr 2021 Marks

A student got 68 % in the board examination. What would be his percentage, if he got 10 % (of the total marks of the subject) more marks in physics, chemistry and mathematics? Total marks are 500 and every paper is of 100 marks.

OPtion

1) 70%
2) 72%
3) 76%
4) 71%
5) 74%
6) 77%
7) 82%
8) 84%
9) 80%
10) None of the above

Solution

68 % of 500 = 340 marks
According to the given condition,
10 % in 3 subjects = 30 marks
Hence total marks = 340 + 30 = 370
= 74 % of 500 marks

Correct Option: 5 Best Solution (3)

27 Apr 2021 Loss

A book seller gets a profit of 10% if he sells a book in 100 rupees. What will be his loss on selling it in 80 rupees?

OPtion

1) 14%
2) 18%
3) 5.5%
4) 5.75%
5) 11.5%
6) 10%
7) 12.5%
8) 15%
9) 12%
10) None of the above

Solution

Original price of the object = 100/1.1
On selling the object in 80 rupee amount received = 80/(100/1.1)
= 88 %
Hence % loss = (100 - 88) % = 12 %

Correct Option: 9 Best Solution (2)

26 Apr 2021 Number

How many numbers of five digits can be formed by using 1, 2, 3, 4, 5, if 4 is necessarily taken at hundred's place and 2 is not allowed at unit's place. Repetition of numbers is not allowed.

OPtion

1) 72
2) 16
3) 12
4) 120
5) 96
6) 24
7) 18
8) 30
9) 15
10) None of the above

Solution

4 is necessarily taken at hundred's place and 2 is not allowed at unit's place,
hence number of methods = 1*3*3*2*1 = 18

Correct Option: 7 Best Solution (3)

23 Apr 2021 Salary

A sum of amount of money is sufficient to pay Naveen’s salary for 28 days and Mohan’s salary for 44 days. The same money is adequate to pay the salary of both for.

OPtion

1) 17.11 days
2) 18.5 days
3) 18.4 days
4) 19 days
5) 19.5 days
6) 16 days
7) 16.5 days
8) 16.11 days
9) 15.27 days
10) None of the above

Solution

Let the total money be Rs.x
Naveen’s 1 day salary = Rs. x/28
Mohan’s 1 day salary = Rs. x/44
(Naveen + Mohan) 1 day salary = Rs(x/28+x/44)
= (7x+11x)/308 =18x/308
x = 308/18 = 17.11
Money is adequate to pay the salary of both for 17.11 days.

Correct Option: 1 Best Solution (3)

22 Apr 2021 Cotton

Ms Pooja had 20.80 m of cotton piece. See cut 7 smaller pieces each of length 0.81 m from it. How many meters of cotton (approx.) were left?

OPtion

1) 5.67 m
2) 16.15 m
3) 14.15 m
4) 15.50 m
5) 16.50 m
6) 14.50 m
7) 15.15 m
8) 16 m
9) 12.37 m
10) None of the above

Solution

Total length of cotton = 20.80 m
Length of 1 small piece of cotton = 0.81 m
Length of 7 small pieced of cotton = 7 x 0.81 = 5.67 m
Hence length of remaining cotton = 20.80 – 5.67 = 15.15 m

Correct Option: 7 Best Solution (2)

21 Apr 2021 Ratio

30% of a number is equal to 70% of another. Ratio of the numbers is

OPtion

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

Solution

30a/100 = 70b/100
3a = 7b
a/b = 3/7

Correct Option: 6 Best Solution (3)

20 Apr 2021 AVERAGE

The average of the marks of maths test of 20 student is 9. If the marks of 5 new students are 9,5,3,2,1 the new average marks is

OPtion

1) 11
2) 10
3) 9.5
4) 9
5) 8
6) 8.5
7) 7
8) 7.5
9) 5
10) None of the above

Solution

Total number of students = 20 + 5 = 25
(20*9)+5+4+3+2+1/25 = 8

Correct Option: 5 Best Solution (2)

19 Apr 2021 Combination

How many words can be formed by using the consonants of the word REMOTE?

OPtion

1) 2
2) 5
3) 6
4) 3
5) 360
6) 7
7) 180
8) 20
9) 10
10) None of the above

Solution

Hence total words are
3*2*1
=6

Correct Option: 3 Best Solution (2)

16 Apr 2021 Train & Speed

A train travels 50 km. distance with speed 50 km./hrs and next 50 km. with speed 60 km./hrs. Average speed will be

OPtion

1) 52
2) 50
3) 60
4) 54
5) 55
6) 54.54
7) 55.5
8) 110
9) 27.27
10) None of the above

Solution

Total distance travelled = 100 km.
Total time taken = (50/50) + (50/60) hrs = 11/6 hrs
so average speed = 100/(11/6) = 600/11 = 54.54

Correct Option: 6 Best Solution (3)

15 Apr 2021 compound interest

What would be the instalment monthly on a loan of 30000 rupee for 3 months, if 12 % yearly compound interest is added monthly

OPtion

10303
2) 10301
3) 10302
4) 10203
5) 10201
6) 10202
7) 10103
8) 10101
9) 10102
10) None of the above

Solution

Let the instalment is A
then according to the given condition,
[(100/101)] A + [(100/101)^2]A + [(100/101)^3]A = 30000
on solving we get A = 10201

Correct Option: 5 Best Solution (0)