A boy was ‘p’ year old ‘r’ years ago. How old will be in ‘(p-r)’ years time? Nurgevers ago Hari was 5 years older than Anushka. If he is now twice as old as she is, find their age.
Hint: We have to first understand the age and time concept clearly and try to not get confused. Here, ago means we should subtract the age from present age. Do calculation on present age. To find required age we have to add and subtract years as given in question.
Complete step-by-step answer: A boy was ‘p’ year old ‘r’ years ago, so to find the current age we have to add r years to p. So the required age of him will be (p + r) years. Now we have to find his age after (p – r) years. So, we have to add (p – r) to his present age. So the required age will be = (p + r) + (p – r) = 2p. Now, it is given that Hari was 5 years older than Anushka. So let us assume age of Anushka is ‘x’ years so age of Hari will be (x + 5) Now, it is given that Hari is twice older than her. So age of Hari will be twice of Anushka i.e. 2x Therefore, we can write, 2x = x + 5 i.e. x = 5. Hence, the age of Anushka is 5 years and the age of Hari is 5 + 5 = 10 years.
Note: To solve this kind of problem we may confuse in Present, past and future age. That is if present age is P, then age 1 year ago was (P – 1) years and age 1 year hence will be (P + 1) years. There can be mistakes where we have to add years or where to subtract.