6, 9, 15, 21, 24, 28, 30
6, 9, 15, 21, 24, 28, 30
[A].
[B].
[C].
[D].
Answer: Option A
Explanation:
Each of the numbers except 28, is a multiple of 3.
[B].
[C].
[D].
Answer: Option A
Explanation:
Each of the numbers except 28, is a multiple of 3.
[B].
[C].
[D].
Answer: Option A
Explanation:
(xn – 1) will be divisibly by (x + 1) only when n is even.
(4915 – 1) = {(72)15 – 1} = (730 – 1), which is divisible by (7 +1), i.e., 8.
[B].
[C].
[D].
Answer: Option A
Explanation:
Let the length of the wire be h.
| Radius = | 1 | mm | = | 1 | cm. | Then, | 
| 2 | 20 | 
| 22 | x | 1 | x | 1 | x h = 66. | |
| 7 | 20 | 20 | 
| h = | 66 x 20 x 20 x 7 | = 8400 cm = 84 m. | ||
| 22 | 
[B].
[C].
[D].
Answer: Option B
Explanation:
| Let the ten’s and unit digit be x and | 8 | respectively. | 
| x | 
| Then, | 10x + | 8 | + 18 = 10 x | 8 | + x | ||
| x | x | 
10×2 + 8 + 18x = 80 + x2
9×2 + 18x – 72 = 0
x2 + 2x – 8 = 0
(x + 4)(x – 2) = 0
x = 2.
[B].
[C].
[D].
Answer: Option C
Explanation:
Go on dividing by 4 to get the next number.
So, 200 is wrong.
		A. 1875/2029
B. 1/2.5
C. 1903/2156
D. 4/9
		A. 7 years
B. 10 years
C. 15 years
D. 20 years
Explanation:
P(1 + R/100)5 = 2P => (1 + R/100)5 = 2
Let P(1 + R/100)n = 8P
=> (1 + R/100)n = 8 = 23 = {(1 + R/100)5}3
=> (1 + R/100)n = (1 + R/100)15 => n = 15 Required time = 15 years.