19, 26, 33, 46, 59, 74, 91
Answer: Option B
Explanation:
Go on adding 7, 9, 11, 13, 15, 17 respectively to obtain the next number.
So, 33 is wrong. It must be 35
1, 3, 10, 21, 64, 129, 356, 777
Answer: Option E
A x 2 + 1, B x 3 + 1, C x 2 + 1, D x 3 + 1 and so on.
So, 356 is wrong.
40960, 10240, 2560, 640, 200, 40, 10
Answer: Option C
Go on dividing by 4 to get the next number.
So, 200 is wrong.
6, 12, 48, 100, 384, 768, 3072
Each even term of the series is obtained by multiplying the previous term by 2.
2nd term = (1st term) x 2 = 6 x 2 = 12
4th term = (3rd term) x 2 = 48 x 2 = 96.
6th term = (5th term) x 2 = 384 x 2 =768.
4th term should be 96 instead of 100.
3, 7, 15, 39, 63, 127, 255, 511
Go on multiplying 2 and adding 1 to get the next number.
So, 39 is wrong.