Question

Sabrina is x years old.

Meghan is twice as old as Sabrina.
Michael is three years younger than Meghan.
The product of Sabrina's and Michael's age is 35.
How old is Meghan?​

Answer 1

Meghan is 10 years old

Explanation:

We can write out the information with equations and then combine the information. Then, we can solve for x and hence solve for Meghan's age.

We write our first variable, x. Meghan (m) is twice as old as Sabrina (x). So we write:

m = 2x

Michael (M) is 3 years younger than Meghan. So we write:

M = m - 3

The product (multiplication) of Sabrina's and Michael's age is 35. So we write:

Mx = 35

To solve for x, we can substitute Meghan's age (2x) into the equation for Michael.

M = 2x - 3

Then, we can substitute this for M in the final equation to solve for x. This will be a quadratic so we factorise to solve it:

x(2x - 3) = 35

2x² - 3x = 35

2x² - 3x -35 = 0

(2x - 7)(x - 5) = 0

x = ⁷⁄₂ or 5

we know it is 5 since ⁷⁄₂ does not work and it is not a whole number. Hence:

m = 2(5)

m = 10

Answer 2

10

Explanation:

If Sabrina is 5 & Michael is 7. (5×7=35)

Michael is 7, & he is 3 yrs younger than Meghan, who is 10. And Meghan is twice as old as Sabrina, when Sabrina is 5 (5×2=10).