42. The difference between the ages of two person is 10 years. Fifteen years ago, the elder one was twice as old as the younger one. The present age of the elder person is
Answer:
Let the ages be x years and (x+10) years respectively.
Then, (x+10) - 15 = 2(x-15)
=> x-5 = 2x-30 => x=25.
Therefore, present age of the elder person = (x+10) = 35 years.
