Calculations Worksheet-4

Calculations Worksheet-4

1. The unit's digit in the product 274 × 318 × 577 × 313 is :

(a) 2                    (b) 3                    (c) 4                    (d) 5

2. The digit in unit's place of the product 81 × 82 × .... × 89 is :

(a) 0                    (b) 2                    (c) 6                    (d) 8

3. The unit's digit in the product (3127)¹⁷³ is :

(a) 1                     (b) 3                    (c) 7                    (d) 9

4. The unit's digit in the product (7⁷¹ × 6⁵⁹ × 3⁶⁵) is :

(a) 1                     (b) 2                    (c) 4                    (d) 6

5. The digit in the unit's place of the number represented by (7⁹⁵ – 3⁵⁸) is :

(a) 0                    (b) 4                    (c) 6                    (d) 7

6. If x is an even number, then x⁴ⁿ, where n is a positive integer, will always have :

(a) zero in the unit's place

(b) 6 in the unit's place

(c) either 0 or 6 in the unit's place

(d) None of these

7. The number of prime factors of (3 × 5)¹² (2 × 7)¹⁰ (10)²⁵ is :

(a) 47                  (b) 60                 (c) 72                  (d) None of these

8. 397 × 397 + 104 × 104 + 2 × 397 × 104 = ?

(a) 250001        (b) 251001         (c) 260101         (d) 261001

9. 186 × 186 + 159 × 159 – 2 × 186 × 159 = ?

(a) 729               (b) 1039             (c) 2019             (d) 7029

10. (475 + 425)² – 4 × 475 × 425 is equal to :

(a) 2500             (b) 3160             (c) 3500             (d) 3600

11. If (64)² – (36)² = 20z, the value of z is :

(a) 70                  (b) 120               (c) 180                (d) None of these

12. (46)² – (?)² = 4398 – 3066

(a) 16                  (b) 28                 (c) 36                  (d) 42

13. is equal to :

(a) 1                     (b) 2                    (c) 689               (d) 1023

14. is equal to:

(a) 2                    (b) 4                    (c) 295                (d) 643

15. The sum of first 45 natural numbers is :

(a) 1035             (b) 1280             (c) 2070             (d) 2140

16. The sum of even numbers between 1 and 31 is :

(a) 16                  (b) 128               (c) 240               (d) 512

17. (51 + 52 + 53 + ..... + 100) is equal to :

(a) 2525             (b) 2975             (c) 3225             (d) 3775

18. How many numbers between 200 and 600 are divisible by 4, 5 and 6 ?

(a) 5                    (b) 6                    (c) 7                    (d) 8

19. How many three–digit numbers are divisible by 6 in all ?

(a) 149                (b) 150                (c) 151                 (d) 166

20. If (1² + 2² + 3² + ..... + 10²) = 385, then the value of (2² + 4² + 6² + ..... + 20²) is :

(a) 770               (b) 1155              (c) 1540              (d) (385 × 385)

Answer Key:

(1)-(a); (2)-(a); (3)-(c); (4)-(c); (5)-(b); (6)-(b); (7)-(d); (8)-(b); (9)-(a); (10)-(a); (11)-(d); (12)-(b); (13)-(b); (14)-(b); (15)-(a); (16)-(c); (17)-(d); (18)-(b); (19)-(b); (20)-(c)