1. Find Next Number in Series `3,6,18,72,?`
The given series is `3,6,18,72,?`
3   6   18   72   360   `xx`2   `xx`3   `xx`4   `xx`5 
`:.` The next number for given series `3,6,18,72` is `360`
2. Find Next Number in Series `1,4,9,16,25,?`
The given series is `1,4,9,16,25,?`
Series are based on square of a number `1=1^2,4=2^2,9=3^2,16=4^2,25=5^2`
`:.` The next number for given series `1,2,3,4,5` is `6`
`:.` Next possible number is `6^2=36`
`:.` The next number for given series `1,4,9,16,25` is `36`
3. Find Next Number in Series `1,9,17,33,49,73,?`
The given series is `1,9,17,33,49,73,?`
1   9   17   33   49   73   97   `+`8   `+`8   `+`16   `+`16   `+`24   `+`24 
`:.` The next number for given series `1,9,17,33,49,73` is `97`
