UPSC NDA Math Model Paper 5

Here, we have to find the decimal equivalent of the binary number 11001010101
⇒20×1+21×0+22×1+23×0+24×1 +25×0 +26×1+27×0+28×0+29×1+210×1
=1+0+4+0+16+0+64+0+0 +512+1024=1621
So, the decimal equivalent of the binary number 11001010101 is (1621)10
Hence, option D is the correct answer.