Kevin is 3 years older than Daniel. Two years ago, Kevin was 4 times as old as daniel.
How old is daniel now?
"Kelvin is 3 years older than Daniel" Let Kelvin be K and Daniel be D
K=D+3 (1) (Well K>D so in order for D to be equal to K we have to add 3 since K Is more than D by 3)
"Two years ago, K was 4 times as old as daniel"
Solve the equation by substituting (2) into (1)
\(4D=D+3\) Subtract D
\(3D=3\) Divide by 3
\(D=1\) Notice that is 2 years ago thus now D+2= 1+2=3
So Daniel = 3 years old now
Kelvin is 6 years old now.