Download : 250 Number Theory Questions with Solutions

1.

The sum of the first 100 natural numbers, 1 to 100 is divisible by ____

- 2, 4 and 8
- 2 and 4
- 2
- 100
- None of these

2.

How many different factors does 48 have, excluding 1 and 48?

- 12
- 4
- 8
- 10
- None of these

3.

10^{25} – 7 is divisible by _____

- 2
- 3
- 9
- Both (2) and (3)

4.

Find the G.C.D of 12x^{2}y^{3}z^{2}, 18x^{3}y^{2}z^{4}, and 24xy^{4}z^{3}

- 6xy
^{2}z^{2} - 6x
^{3}y^{4}z^{3} - 24xy
^{2}z^{2} - 24xy
^{3}z^{2} - 18x
^{2}y^{2}z^{3}

5.

What is the value of M and N respectively? If M39048458N is divisible by 8 & 11; where M & N take integer values from 0 to 9, inclusive?

- M = 7; N = 8
- M = 8; N = 6
- M = 6; N = 4
- M = 5; N = 4
- M = 4; N = 6

6.

48 students have to be seated such that each row has the same number of students as the others. If at least 3 students are to be seated per row and at least 2 rows have to be there, how many arrangements are possible?

- 4
- 10
- 8
- 7
- 6