There is a group of 8 lions. One lion leaves the group and a new lion joins the group. Due to this, average age of lions becomes same as the average 2 years ago. If the member left was aged 42. Then what is the age of new lion?

When one lion leaves and another joins, keeping the group size at 8, the average returns to what it was 2 years ago. This means the new lion's age must be 2 years younger than the lion who left, since the group collectively 'lost' 8 years (8 lions × 2 years = 16 years) to reverse 2 years of aging. If the departed lion was 42, the new lion is 42 - 16 = 26.