The average age of 4 sisters is 7 years. If we add the age of mother, the average increases by 6 years. Find the age of mother?

Explanation

Average age of 4 sisters = 7 years Total age of 4 sisters = 7 × 4 = 28 years Average age of all members including mother = 7 + 6 = 13 years Total age of all members (Mother + 4 sisters)= 13 × 5 = 65 years Mother age = (65 – 28) years = 37 years