John Is 2 Time As Old As His Friend Peter. Peter Is 5 Years Older Than Alice. In 5 Years John Will Be Three Times As Old As Alice. How Old Os Peter No

John is 2 time as old as his friend Peter. Peter is 5 years older than Alice. In 5 years John will be three times as old as Alice. How old os peter now ? Please even just equation.

  Let x be Johns age
y be Peters age
z be Alices age
x = 2y ---equation 1
y = z + 5 ---equation 2
x +5 = 3(z + 5) ---equation 3
Substitute both equations 1 and 2 to 3
x + 5 = 3(z + 5)
2y + 5 = 3y
3y -2y = 5
y = 5

Therefore Peter is 5 years old