A joke about walking with grandpa.

Calculate the speed first: it takes eight minutes for Xiao Ming to walk around and ten minutes for Grandpa to walk around. So Xiao Ming's speed is 1/8 laps per minute, and Grandpa's speed is110 laps per minute.

The first question: it can be understood as the time for two people to complete a lap together.

So 1 (circle) ÷ (1/8+110) = 40/9 (minutes) = 4 and 4/9 (minutes).

The second question: it can be understood that two people walk a circle and subtract their speed.

So 1 (circle) ÷ (1/8-110) = 40 (minutes).

A: (1) Meet in 40/9 minutes; (2) After 40 minutes, Xiao Ming and his grandfather passed by.