IndiaBIX

Aptitude - Numbers

Exercise : Numbers - General Questions
76.
A number when divide by 6 leaves a remainder 3. When the square of the number is divided by 6, the remainder is:
0 
1
2
3
Answer: Option
Explanation:

Let x = 6q + 3.

Then, x2 = (6q + 3)2

   = 36q2 + 36q + 9

   = 6(6q2 + 6q + 1) + 3

Thus, when x2 is divided by 6, then remainder = 3.

77.
The sum of the two numbers is 12 and their product is 35. What is the sum of the reciprocals of these numbers ?
12
35
1
35
35
8
7
32
Answer: Option
Explanation:

Let the numbers be a and b. Then, a + b = 12 and ab = 35.

a + b = 12          1 + 1 = 12
ab 35 b a 35

Sum of reciprocals of given numbers = 12
35

78.
What will be remainder when 17200 is divided by 18 ?
17
16
1
2
Answer: Option
Explanation:

When n is even. (xn - an) is completely divisibly by (x + a)

(17200 - 1200) is completely divisible by (17 + 1), i.e., 18.

   (17200 - 1) is completely divisible by 18.

   On dividing 17200 by 18, we get 1 as remainder.

79.
If 1400 x x = 1050. Then, x = ?
1
4
3
5
2
3
3
4
None of these
Answer: Option
Explanation:
1400 x x = 1050      x = 1050 = 3
1400 4
80.
(12 + 22 + 32 + ... + 102) = ?
330
345
365
385
Answer: Option
Explanation:

We know that (12 + 22 + 32 + ... + n2) = 1 n(n + 1)(2n + 1)
6

Putting n = 10, required sum = 1 x 10 x 11 x 21 = 385
6

Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers