When I was 24, my mother was twice my age. Now I am 44, how old is my mother?

From the given data,

when my age is 24, my mothers age is double of my age 

=> 48 yrs is my mothers age

=> Difference is 48 - 24 = 24 years.

When my age is 44

=> My mother is 44 + 24 = 68 years aged.