Question 1085332
Let a = Kevin's age now
His age in 10 years tripled is 3(a + 10)
His age 4 years ago multiplied by 5 is 5( a - 4)
Set these equal to each other, and solve for a:
3(a + 10) = 5(a - 4)
2a = 50 
a = 25
Ans: 25 years old