Anjum was 1/3 as young as her grandfather 15years ago if the sum of their ages is 110 how old is anjum grandfather

Answer 1

(1/3)(g-15) = a-15

g + a = 110
so
a = 110-g

(1/3)(g-15) = (110 - g) -15
g - 15 = 3 (95-g) = 285 - 3 g
4 g = 300
g = 75