Without calculating we can say that the system with the original cost $60 ( the cheaper system ) had a greater percent decrease.
This is because $10 is a greater percentage of $60 than it is of $90 ( if we calculate it is 16.66% in the first case and 11.11% in the second case).
Answer: 
Step-by-step explanation:
^{2} +(-3-3)^{2} \\\sqrt64+36\\\sqrt100\\=10](https://tex.z-dn.net/?f=%5Csqrt%5Bn%5D%28-4-4%29%5E%7B2%7D%20%2B%28-3-3%29%5E%7B2%7D%20%5C%5C%5Csqrt64%2B36%5C%5C%5Csqrt100%5C%5C%3D10)
Answer:
The expected cost is $8.75
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Step-by-step explanation:
Given

--- If Bob and Anna meet
--- If Bob and Anna do not meet
Required
The expected cost of Bob's meal
First, we list out all possible time both Bob and Anna can select
We have:



The outcome of them meeting at the same time is:


The probability of them meeting at the same time is:



The outcome of them not meeting:


The probability of them meeting at the same time is:



The expected cost is then calculated as:



Take LCM



<em>The expected cost is $8.75</em>