Find the invalid no.from the following series 3, 7, 15, 27, 63, 127, 255
Pick
A) 3	B) 15	C) 27	D) 127	E) 255
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