Question 227094
Let {{{j}}}= John's age now
Let {{{m}}}= Mark's age now
Let {{{p}}}= Paul's age now
given:
(1) {{{j = 3p - 2}}}
(2) {{{m = p + 15}}}
(3) {{{j + p + m = 103}}}
Substitute (1) and (2) into (3)
(3) {{{j + p + m = 103}}}
{{{3p - 2 + p + p + 15 = 103}}}
{{{5p + 13 = 103}}}
{{{5p = 90}}}
{{{p = 18}}}
and, from (1)
(1) {{{j = 3p - 2}}}
{{{j = 3*18 - 2}}}
{{{j = 54 - 2}}}
{{{j = 52}}}
and, from (2)
(2) {{{m = p + 15}}}
{{{m = 18 + 15}}}
{{{m = 33}}}
John is 52, Paul is 18, Mark is 33
check:
(3) {{{j + p + m = 103}}}
{{{52 + 18 + 33 = 103}}}
{{{103 = 103}}}
OK