**Numbers Aptitude Questions & Answers with explanation– Test Paper 4**

1) Which of the following is the output of 495 * 495 – 105 * 105?

- 234000
- 360000
- 300000
- 350000

The Correct answer is (1)

Answer with explanation:

Apply formula; (a2 – b2) = (a – b) (a+b)

495 x 495 – 105 x 105

= (4952 – 1052)

= (495 – 105) (495 + 105)

= 390 * 600

= 234000

2) What is the unit digit in the product of 853 * 1346 * 452 * 226?

- 4
- 5
- 6
- 8

The Correct answer is (3)

Answer with explanation:

Pick up the unit digit of each number and multiply them;

3 in 853

6 in 1346

2 in 452

6 in 226

3 * 6 * 2 * 6 = 216 (consider the unit digit in the product)

So, the unit digit in the product of 853 * 1346 * 452 * 226 is 6.

3) If two-third of three-fourth of a number is 34, find the 20% of that number?

- 13
- 13.6
- 14
- 14.6

The Correct answer is (2)

**Answer with explanation:**

Let the number is X.

As per question;

4) What is the sum of all odd numbers up to 240?

- 14400
- 13400
- 12400
- 11400

The Correct answer is (1)

**Answer with explanation:**

Number of odd numbers up to 240 =^{240}⁄_{2}= 120

Sum of first n odd numbers = n^{2}

n = 120

Required sum = 120^{2 }= 14400

5) What are the different prime factors of 2400?

- 2
- 3
- 4
- 5

The Correct answer is (B)

**Answer with explanation:**

L.C.M of 2400 = 2 x 2 x 2 x 2 x 2 x 3 x 5 x 5

The different prime factors are 3 (2, 3 and 5).

Also See the Test Paper 5

[…] Also see Test Paper 4 […]