Find the invalid no.from the following series 3, 7, 15, 27, 63, 127, 255  Choose the most appropriate option
A) 18 B) 19 C) 27 D) 29 E) 31
Go on multiplying the number by 2 and adding 1 to it to get the next number.So, 27 is wrong.   27
<result>C</result>
Find the invalid no.from the following series 3, 7, 15, 27, 63, 127, 255