A mother is 21 years older than her newborn dughter. How old will be the daughter when her age is 1/4 that of her mother's? Explain your workings

Let x = daughter's age, then x+21 = mother's age.

x = (x+21)/4

Solve for x.

To find out the age of the daughter when her age is 1/4 of her mother's age, we need to start by setting up an equation.

Let's assume the current age of the daughter is x.
According to the given information, the mother is 21 years older than her newborn daughter, so the mother's age would be (x + 21).

To find the daughter's age when it is 1/4 of the mother's age, we need to set up the following equation:

x = (1/4) * (x + 21)

To solve this equation, we can start by multiplying both sides of the equation by 4 to simplify the equation:

4x = x + 21

Next, we can subtract x from both sides of the equation to isolate the variable x:

4x - x = 21
3x = 21

To solve for x, we need to divide both sides of the equation by 3:

3x/3 = 21/3
x = 7

So, the daughter is currently 7 years old. We can check if the daughter's age will be 1/4 of the mother's age at 7 + 21 = 28 years old.

Let's calculate the daughter's age when she is 28 years old:

(1/4) * (28 + 21) = (1/4) * 49 = 12.25

Therefore, when the daughter is 28 years old, her age will be 1/4 that of her mother's age, which is 12.25.