Question 1210615
{{{x}}}=number of cookies Lauri baked.
{{{(2/3)x}}}=number of cookies Anže baked
If we assume that "after the morning rush" and "by the end of the day" are the same time, and the time when
Anže had 10 fewer cookies left than the number he had originally baked, and
Lauri had 1/4 as many cookies left as Anže,
we have enough data to solve the problem.
At the end, Anže had {{{(2/3)x-10}}} cookies left,
while Lauri had {{{(1/4)((2/3)x-10)}}} cookies left.
The difference is:
{{{(2/3)x-10-(1/4)((2/3)x-10)=(1-1/4)((2/3)x-10)=(3/4)((2/3)x-10)}}} cookies, and we are told that
{{{(3/4)((2/3)x-10)=30}}}Multiplying both side times {{{4/3}}}  , we get
{{{(2/3)x-10=40}}}-->{{{(2/3)x=50}}}-->{{{x=50(3/2)}}}-->{{{x=highlight(75)}}}