Answer:
Peter is 20 now
Step-by-step explanation:
Now
P = A +5 and J = 2P
plug in P in J = 2P = 2(A+5) =2A +10
In 5 years
J+5 = 3A
2A+10+5 = 3A
2A + 15 = 3A subtract 2A from each side
A = 15 so Alice is 15 now
P = A+5 =15+5= 20 so Peter is 20 now
Let's check :
P=20 J=40 A=15
in 5 years J = 45 A =3*15=45