Question

计算(1十1/2)x(1一1/2)x(1十1/3)x(1一1/3)x(1十1/4)x(1-1/4)x…x(1十1/12)

Answer 1

=(1-1/2)(1+1/2)(1-1/3)(1+1/3)(1-1/4)(1+1/4)……(1-1/12)(1+1/12)

=1/2 × 3/2×2/3 × 4/3×3/4 ×……× 11/12 ×13/12

=1/2×13/12

=13/24