26÷(1- 1 2+1 - 1 3+1 - 1 1+4 )× 1 2+1 =26÷(1- 1 3 - 1 4 - 1 5 )× 1 3 =26÷ 13 60 × 1 3 =40(岁)答:王先生40岁.