Choose the correct number to replace the incorrect from the alternatives given to keep the series in order 3, 7, 13, 21, 33, 43, 57, 73.
A22
B52
C31
Dnone of these
Answer:
C. 31
Read Explanation:
From left to right, the difference between adjascent terms increases by 2. But in the case of 4th & 4th terms, the difference is increased by 4. So the correct term will be 31.