Question

kevin is 3 times as old as daniel. 4 years ago, kevin was 5 times as old as daniel.
how old is kevin now?

Explanation:

Step1: Define variables

Let $D$ = Daniel's current age, $K$ = Kevin's current age.
From the problem: $K = 3D$

Step2: Set up 4-years-ago equation

4 years ago, Kevin's age was $K-4$, Daniel's was $D-4$. So:
$K - 4 = 5(D - 4)$

Step3: Substitute $K=3D$ into equation

$3D - 4 = 5(D - 4)$

Step4: Expand and solve for $D$

$3D - 4 = 5D - 20$
$-4 + 20 = 5D - 3D$
$16 = 2D$
$D = 8$

Step5: Find Kevin's current age

$K = 3D = 3\times8$

Answer:

24