I was born in ABCD which is the year of the Christian era (A.D.).
In 1997, I became (A+B+C+D) years old.
How old was I in 1997 ?
In 1997, I became (A+B+C+D) years old.
How old was I in 1997 ?
Answer
Solution
1997 - (1000 × A + 100 × B + 10 × C + D) = A + B + C + D.
Then, 1997 = 1001 × A + 101 × B + 11 × C + 2 × D.
Since A, B, C, and D is the integer of ones digit respectively.
The number applicable from A to D in order is 1 for A, 9 for B, 7 for C, 5 for D.
The age to be found is 22 years old which comes from 1997 - 1975.
22 years old
1997 - (1000 × A + 100 × B + 10 × C + D) = A + B + C + D.
Then, 1997 = 1001 × A + 101 × B + 11 × C + 2 × D.
Since A, B, C, and D is the integer of ones digit respectively.
The number applicable from A to D in order is 1 for A, 9 for B, 7 for C, 5 for D.
The age to be found is 22 years old which comes from 1997 - 1975.
