Question

My grandfather is 90 years old. He has gone around the sun how many times

Answer 1

as he is 90 years he has gone 90 times around the sun
because earth takes 1 round around the sun in 1 year

Answer 2

Our earth takes 365 days or 1 year to complete one revolution around sun. As earth moves, objects on earth also moves. As Grandfather is 90 years old, earth must have gone through 90/1 revolutions .

Hence, Grandfather has gone through sun for 90 times .