Solution: The given number series is 720, 732, 708, 742, 696
 
720
720 + 12 = 732
732 - 24 = 708
708 + 36 = 744 (Not 742)
744 - 48 = 696
 
Hence, the odd man in the given number series is 742.

Solution: 4             3             4             7               15        ? ×1-1      ×1+1       ×2-1       ×2+1           ×3-1
 
15x3 - 1 = 45 - 1 = 44

Solution: Here the given number series is 270, 261, 279, 252, 289, 243
270 - 9 = 261
261 + 18 = 279
279 - 27 = 252
252 + 36 = 288 (not equals to 289)
288 - 45 = 243
 
Hence, the odd number in the given number series is 289.

Solution: Arithmetic Series ::
 
An Arithmetic Series is a series of numbers in which each term increases by a constant amount.
 
How to find the sum of the Arithmetic Sequence or Series for the given Series ::
 
When the series contains a large amount of numbers, its impractical to add manually. You can quickly find the sum of any arithmetic sequence by multiplying the average of the first and last term by the number of terms in the sequence.
That is given by Sn = n(a1 + an)2 Where n = number of terms, a1 = first term, an = last term
 
Here Last term is given by an = a1 + n-1d where d = common difference
 
Now given Arithmetic Series is 
 
2, 5, 8, 11,...
 
Here a1 = 2,  d = 3, n = 36 
Now, an= a1 + n - 1d a36= 2 + 36 - 13 = 105 + 2 = 107 
 
Now, Sum to 36 terms is given by
 
S36 = 36(2 + 107)2 = 36 x 1092 = 39242 = 1962
 
 
 
Therefore, Sum to 36 terms of the series 2, 5, 8, 11,... is 1962.

Solution: ORU

Solution: 191

Solution: 531

Solution: 327

Solution: This is an alternating division and addition series: First, divide by 2, and then add 8.

Solution: √180 km