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.

Answer 1

Let's start by setting up equations based on the information given:

Let x be John's age now and y be his sister's age now.

We know that John’s age is 3/5 of his sister’s age, so we can write the equation:

x = 3/5 * y

In four years time, John will be x + 4 years old and his sister will be y + 4 years old. We are also given that the total age in four years time is 24 years, so we can write the equation:

(x + 4) + (y + 4) = 24

Now, we can substitute the expression for x from the first equation into the second equation:

(3/5 * y + 4) + (y + 4) = 24
3/5y + 4 + y + 4 = 24
3/5y + y + 8 = 24
8/5y + 8 = 24
8/5y = 16
y = 10

Now that we have found y, we can substitute it back into the first equation to find x:

x = 3/5 * 10
x = 6

Therefore, John is 6 years old now.