Explanation:
Let Darren age be x
and since they are odd consecutive numbers,
his two siblings age will be
1st sibling is x+2
2rd sibling is x+2+2 = x+4
If the sum of their ages is 51
that is, x+x+2+x+4= 51
3x+6 = 51
3x+6-6=51-6
3x = 45
3x/3 = 45/3
x = 15 yrs
Since x is 15, therefore Darren age is 15
and 1st sibling is x+2
= 15+2
= 17 yrrs
and 2rd sibling is x+4
= 15+4
= 19 yrs