Answer : 4.5 × 10⁴ square inches can be washed per hour.
Step-by-step explanation :
As we are given that an area can be washed at a rate of 4,900 cm²/min. Now we have to determine the square inches can be washed per hour.
Given conversions are:
1 cm = 0.39 in and 1 hr = 60 min
As, 1 cm² = (0.39)² in² and 1 min = 1/60 hr
So, 
Now we have to determine the square inches can be washed per hour.
As,
So, 
Therefore, 4.5 × 10⁴ square inches can be washed per hour.
Answer:
Mom: $30
Charlie: $10
Step-by-step explanation:
You have to find how much percent of 40 for the price that they each pay.
His mom pays 75%, so that is $30.
And Charlie has to pay $10 because that is how much is left.
The midpoint is their average.
.. ((15, -1) +(9, -5))/2 = ((15+9)/2, (-1-5)/2) = (12, -3)
Explanation:
a)
b) First, we have that
On the other hand,
Therefore, both expressions are equal. This makes sense, because selecting k elements from a group of n is the same than specify which elements you will not select. In order to specify those elements you need to select the n-k elements that will not be selected. Hence, each time you are selecting k from n, you are also selecting n-k from n, and from that reason both combinatorial numbers are equal.
