Question

Kofi is 7times as old as his daughter. I n 5years time he will be 4 times as old as his daughter.what will their ages​

Answer 1

Answer

Kofi is 35

His daughter is 5

Explanation

(If it's right, please make this a brainlest answer)

Kofi is 7 times his daughter (and 35 is 7 times 5)

In 5 years, Kofi will be 40, and his daughter will be 10 (and 40 is 4 times 10)

So Kofi is 35, then 40

And his daughter is 5, then 10

Answer 2

Let k be Kofi's age, and d be his daughter's age.

As of today, Kofi is 7 times as old as his daughter, which translates to

$k=7d$

In 5 years time he will be 4 times as old as his daughter, which translates to

$k+5=4(d+5)$

In fact, in 5 years their age will be the current one plus 5, and we know that Kofi will be 4 times as old as his daughter.

Rewrite the second equation as

$k+5=4(d+5) \iff k+5 = 4d+20 \iff k = 4d+15$

Now we have the system

$\begin{cases}k=7d\\k = 4d+15\end{cases}$

Use the first equation to write the second as

$7d = 4d+15 \iff 3d=15 \iff d=5$

And we can deduce

$k=7d=7\cdot 5=35$

So, Kofi is 35, and his daugter is 5.