Numbers

1. (935421 x 625) = ?
A. 542622125	B. 584632125
C. 544638125	D. 584638125

2. Which of the following is a prime number ?
A. 9	B. 8
C. 4	D. 2

3. What is the largest 4 digit number exactly divisible by 88?
A. 9944	B. 9999
C. 9988	D. 9900

Answer : Option A

Explanation :

Largest 4 digit number = 9999

9999 ÷ 88 = 113, remainder = 55

Hence largest 4 digit number exactly divisible by 88 = 9999 - 55 = 9944

4. {(481 + 426)2 - 4 x 481 x 426} = ?
A. 3025	B. 4200
C. 3060	D. 3210

Here, the given statement is like (a + b)² - 4ab where a= 481 and b = 426

(a + b)² - 4ab = (a² + 2ab + b²) - 4ab = a² - 2ab + b² = (a - b)²

Hence {(481 + 426)² - 4 x 481 x 426} = (481 - 426)² = 55² = 3025

5. (64 - 12)2 + 4 x 64 x 12 = ?
A. 5246	B. 4406
C. 5126	D. 5776

Here, the given statement is like (a - b)² + 4ab where a= 64 and b = 12

(a - b)² + 4ab = (a² - 2ab + b²) + 4ab = a² + 2ab + b² = (a + b)²

Hence (64 - 12)² + 4 x 64 x 12 = (64 + 12)² = 76² = 5776

6. 121 x 54 = ?
A. 68225	B. 75625
C. 72325	D. 71225

Answer : Option B

Explanation :

121×54=121×(102)4=121×1000016=7.5625×10000=75625