Question 1105316
 Geoffrey is twice as old as his friend Peter. Peter is 5 years older than Alice. In 5 years, Geoffrey will be three times as old as Alice. How old is Peter now? 
-----
Equations:
g = 2P
P = A+5
g+5 = 3(A+5)
--------
Substitute for "g" and "A" to get::
2P +5 = 3(P-5)+3*5
2P + 5 = 3P
P = 5 yrs (Peters age now)
-----------------
Cheers,
Stan H.
---------------