Grandpa's age is 6 times that of Liang Liang, and Liang Liang is 1 times his own age, so his age is (6+ 1)= 7 times that of Liang Liang, which is equal to 105, so Liang Liang's age is: 105 ÷ 7 = 65435.

Liang Liang's age is:105 (6+1) =15 years old.

Grandpa's age is: 15×6=90 years old.