John’s age is 3/5 of his sister’s age. The total age in four years time is 24 years. How old is John now? Show steps and use try check and revise.
Let's start by defining the variables:
- John's age now: J
- Sister's age now: S
From the given information, we know that John's age is 3/5 of his sister's age. Mathematically, this can be represented as:
J = (3/5)S
In four years time, John will be J+4 years old, and his sister will be S+4 years old. The total age at that time is 24 years, so:
(J+4) + (S+4) = 24
Now, we can substitute the value of J from the first equation into the second equation:
(3/5)S + 4 + S + 4 = 24
(8/5)S + 8 = 24
(8/5)S = 16
S = 10
Now that we have found the sister's age, we can find John's age using the first equation:
J = (3/5)*10
J = 6
Therefore, John is currently 6 years old. Let's check this by substituting the values back into the total age equation:
(6+4) + (10+4) = 14 + 14 = 24
The total age in four years time is indeed 24 years, so the solution is correct. John is currently 6 years old.