A mother said to her son, “I was as old as you are at present at the time of your birth.” If the mothers age is 36 years now the sons age 6 years back will be how many years?
12
4
11.5
12.5
Explanation:
Let, the mother's present age be M and his son's present age be S.
Given, when his son was born, she was the same age as her son. Now since the son's age is S, he would be born S years ago.
Hence, mother's age S years ago = M - S.
But her, age was same as the present age of son.
→ M - S = S
→ M = 2S
Now, we know her present age is 36. So,
36 = 2S
→ S = 36/2
→ S = 18 years.
Son's present age is 18 years. Hence, his age 6 years back would be 12 years.
Let, the mother's present age be M and his son's present age be S.
Given, when his son was born, she was the same age as her son. Now since the son's age is S, he would be born S years ago.
Hence, mother's age S years ago = M - S.
But her, age was same as the present age of son.
→ M - S = S
→ M = 2S
Now, we know her present age is 36. So,
36 = 2S
→ S = 36/2
→ S = 18 years.
Son's present age is 18 years. Hence, his age 6 years back would be 12 years.