Mma can see that 2.09 is closer to 2 than 2.36.
You take 720 and divide by 4 for the 4 weeks. Then you divide by 6 for each of the day and then you reach your answer.
15=pants
d less than pants means
15-d
5 of them
5(15-d)=cost of shirts
so total cost=15+5(15-d)
X=0.84....................