Solution
$$15\times\ 2+1 = 30+1 = 31$$
$$31\times\ 2+1 = 62+1 = 63$$
$$63\times\ 2+1 = 126+1 = 127$$
$$127\times\ 2+1 = 254+1 = 255$$
Here 63 will come in place of question mark.
Create a FREE account and get:
- Free SSC Study Material - 18000 Questions
- 230+ SSC previous papers with solutions PDF
- 100+ SSC Online Tests for Free
