20 MCQs about Basic Mathematics and Statistics : Important for NRB Officers and Other Competitive Exams

1) A and B can do a piece of work in 72 days, B and C can do it in 120 days, and A and C can do it in 90 days. In what time can A alone do it?

a) 150 days      b)  120 days    c) 100 days      d)  80 days

 

2) The average of 8 numbers is B, and one of the numbers is 14. If 14 is replaced with 28, what is the new average in terms of B?

a) B+7/2  b) B+1/2  c) B+2     d)  2B+l

 

3) Six bells commence tolling together and toll at intervals of 3, 6, 12, 15, 21 and 24 seconds respectively. In 30 minutes, how many times does they toll together?

a) 1        b) 2      c) 3               d) 4                  

 

4) lf "b" is a positive number, 40% of "b" is what % of 400b?

a) 0.01     b) 0.1       c) 1       d)  100

 

5) A man sold 250 chairs and had a gain equal to the selling price of 50 chairs. His profit percentage is:

a) 5%             b) 10%            c) 25%       d)  50%

 

6) A train 100 meters long travelling at 40 kmph overtakes another train travelling in the same direction at 30 kmph and passes it completely in 126 seconds. The length of the second train is:

a) 200m      b) 225 m                 c) 250 m            d) 275 m

 

7) The difference between simple and compound interest on a sum of money at 5% per annum is Rs. 25. The sum is:

a) Rs. 5,000     b) Rs. 10,000     c) Rs. 4,000   d) None of these

 

8) The third proportion to the numbers 5 and 10 is:

a) 20                   b) 2.5         c) 25            d) 30

 

9) If 'n' is a number such that (-8)²ⁿ = 2⁸⁺²ⁿ, the value of 'n' is:

a) 1/2           b) 3/2            b) 2             d) 4

 

10) If 10 is added to an integer, the result will be at most 18. The integer is:

a) X<=8      b) X>=8              c) X<=3        d) None of these

 

11) The number of +ve integers less than 100 having a remainder of 3 when divided by 7 is:

a) 10                 b) 14       c) 15        d) 16

 

12) Find out the wrong number in the following sequence:

1, 8, 27, 64, 124, 216, 343.

a) 8               b) 27           c) 64         d) 124

 

13) If 3, x, 7 are in H.P, the value of 'x' is:

 a) 15/2            b) 7/4             c) 21/5           d) 25/4

 

14) The sum of a number and 16 times its reciprocal is 8, the number is:

   a) 4          b) 5         c) 6                   d) 7

 

15) A survey shows that 74% of the students like apples, where as 68% like oranges. The percentage of the students who like both apples and oranges is:

 a)  40              b) 42            c) 43              d) 44

 

16) In an individual series, each variable value has:

a) Same frequency                   b) Frequency one

c) Varied frequency                  d) Frequency two

 

17) The correct relation among AM, GM, and HM is:

a) AM=BM=HM                        b) GM>=AM>=HM

c) HM>=GM>=AM                   d) AM>=GM>=HM

 

18) Frequency must be regular to compute:

  a) Mean                 b) Median        c) Mode         d) s.d.

 

19) Limits for population correlation coefficients are:

a) r-PE(r)                        b) r+-PE(r)

c)  r+PE(r)                      d) All of these

 

20) Tossing a coin probability of getting a head is:

a) 0                 b) 1           c) 0.5            d) None of these