UPSC NDA Math Model Paper 4

Here, we have to find the decimal equivalent of the binary number 1000111
⇒20×1+21×1+22×1+23×0 +24×0+25×0+26×1
=1+2+4+0+0+0+64 =71
So, the decimal equivalent of the binary number 110110 is (54)10
Hence, option B is the correct answer.