Question 841699
peter is 1/4 as old as john.
p = {{{1/4}}}j
multiply both sides by 4
4p = j
 in 5 years time, peter will be 1/3 as old as john.
p + 5 = {{{1/3}}}(j+5)
multiply both sides by 3
3(p+5) = j + 5
3p + 15 = j + 5
3p = j + 5 - 15
3p = j - 10
Replace j with 4p
3p = 4p - 10
10 = 4p - 3p
p = 10
 how old is peter now? 10 yrs old