Question 1196652


let the number of marbles Don has be {{{d}}} and the number of marbles Mark has be {{{m}}}

if Don has {{{3}}} more than {{{3}}} times the number of marbles Mark has, we have

{{{d=3m+3}}}...........eq.1


if the total number of marbles is{{{ 99}}}, we have

{{{d+m=99}}}............eq.2, substitute {{{d}}} from eq.1

{{{3m+3+m=99}}}...........solve for {{{m}}}

{{{4m=99-3}}}

{{{4m=96}}}

{{{m=96/4}}}

{{{m=24}}}

go to

{{{d=3m+3}}}...........eq.1, substitute {{{m}}}

{{{d=3*24+3}}}

{{{d=75}}}

answer:

Don has {{{75}}} and  Mark has {{{24}}} marbles.