Question 1198763
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<pre>

From the problem, we see that the amount of money 22.45-6.70 = 15.75 dollars

was spent to buy 1+4 = 5 milkshakes on Saturday.


From it, we conclude that each milkshake costs  {{{15.75/5}}} = 3.15 dollars.   <U>ANSWER</U>
</pre>

The problem is just solved.


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To solve the problem, I do not need to answer questions printed in the first line of the post.


I simply ignore them, since they do not help me to solve the problem.


Also, the info about their purchases on Thursday is irrelevant.


Regarding Thursday, we only need the balance on the card on Thursday late evening.