Answer:
(B)
Step-by-step explanation:
Given: From the figure, it is given that the length of the base is 4 feet and slant height is 7 feet.
To find: The Surface are of Pyramid.
Solution: From the figure, it is given that the length of the base is 4 feet and slant height is 7 feet.
Now, surface area of the Pyramid is given as:
where p is the perimeter and l is the slant height.
Now, area of base is given as:
And, the surface area is given as:
Hence, option B is correct.
Answer:
<u>135.73 ounces</u> of a silver alloy that costs $5.50 per ounce should be mixed.
Step-by-step explanation:
Given:
A silver alloy that costs $5.50 per ounce should be mixed with one that costs $7.00 per ounce to make a new 30 ounce alloy that costs $6.40 per ounce.
Now, to find the ounces of silver alloy.
Let the silver costs $5.50 per ounce be
And the silver costs $7.00 per ounce be
So, the total ounce make a new alloy:
....(1)
Now, the total costs of silver alloy:
Putting the value of from equation (1) in the place of
:
<em>Subtracting both sides by 210 we get:</em>
<em>Dividing both sides by -1.5 we get:</em>
Therefore, 135.73 ounces of a silver alloy that costs $5.50 per ounce should be mixed.