Question

Convert the binary number 10101 to its base 10 equivalent. 12 21 22 31

Answer 1

10101₂ = 1×2⁴ + 0×2³ + 1×2² + 0×2¹ + 1×2⁰

10101₂ = 16 + 0 + 4 + 0 + 1

10101₂ = 21

Answer 2

Here see below

$\\ \sf\Rrightarrow (10101)_2$

$\\ \sf\Rrightarrow 1\times 2^0+0\times 2^1+1\times 2^2+0\times 2^3+1\times 2^4$

$\\ \sf\Rrightarrow 1+4+16$

$\\ \sf\Rrightarrow (21)_{10}$