1. 16, 33, 65, 131, 261, (....)
A. 523
B. 521
C. 613
D. 721
Answer: Option A
Explanation:
Each number is twice the preceding one with 1 added or subtracted alternatively.
So, the next number is (2 x 261 + 1) = 523.
2. 10, 5, 13, 10, 16, 20, 19, (....)
Answer: Option B
Explanation:
There are two series (10, 13, 16, 19) and (5, 10, 20, 40), one increasing by 3 and the other multiplied by 2.
3. 1, 4, 9, 16, 25, 36, 49, (....)
Answer: Option C
Explanation:
Numbers are [latex]{1}^{2}[/latex], [latex]{2}^{2}[/latex], [latex]{3}^{2}[/latex], [latex]{4}^{2}[/latex], [latex]{5}^{2}[/latex], [latex]{6}^{2}[/latex], [latex]{7}^{2}[/latex].
So, the next number is [latex]{8}^{2}[/latex] = 64.
4. 8, 7, 11, 12, 14, 17, 17, 22, (....)
Answer: Option B
Explanation:
Greatest number of 4-digits is 9999.
There are two series (8, 11, 14, 17, 20) and (7, 12, 17, 22) increasing by 3 and 5 respectively.
5. 7, 8, 18, 57, 228, 1165, 6996
Answer: Option D
Explanation:
Let the given numbers be A, B, C, D, E, F, G.
Then, A, A x 1 + 1, B x 2 + 2, C x 3 + 3, D x 4 + 4, E x 5 + 5, F x 6 + 6 are the required numbers.
Clearly, 228 is wrong.