Answer :
Let us call them a, b and c
we know that
a+1=b
a+2=c
a+2b=12+c
we can deduce the following:
a+2(a+1)=12+(a+2)
3a+2=a+14
2a=12
a=6
so b would be 7 and c would be 8
Makes sense ?
we know that
a+1=b
a+2=c
a+2b=12+c
we can deduce the following:
a+2(a+1)=12+(a+2)
3a+2=a+14
2a=12
a=6
so b would be 7 and c would be 8
Makes sense ?