Answer :
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
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
[tex]k=7d[/tex]
In 5 years time he will be 4 times as old as his daughter, which translates to
[tex]k+5=4(d+5)[/tex]
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
[tex]k+5=4(d+5) \iff k+5 = 4d+20 \iff k = 4d+15[/tex]
Now we have the system
[tex]\begin{cases}k=7d\\k = 4d+15\end{cases}[/tex]
Use the first equation to write the second as
[tex]7d = 4d+15 \iff 3d=15 \iff d=5[/tex]
And we can deduce
[tex]k=7d=7\cdot 5=35[/tex]
So, Kofi is 35, and his daugter is 5.