Question

B=1+1/2+1/2^2+1/2^3+...+1/2^99+1/2^100+1/2^100

Answer 1

B=1+1/2+1/2^2+1/2^3+...+1/2^99+1/2^100+1/2^101

2B=2+1+1/2+1/2^2+...+1/2^98+1/2^99+1/2^100

2B-B=2+1+1/2+1/2^2+...+1/2^98+1/2^99+1/2^100-(1+1/2+1/2^2+1/2^3+...+1/2^99+1/2^100+1/2^101)

=>B=2+1/2^100-1/2^101

=>B=2+2/2^101-1/2^101

    B=21/2^101 (2 là phần nguyên, 1/2^101 là phần phân số)