the average age of four men is 40. If the sum of the ages of three of them is 115, what's the age of the fourth man?
1 answer:
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Correct option B) .
<u>Step-by-step explanation:</u>
We have the following figure attached as shown below.
Now, this triangular prism have 2 similar right angled surfaces and 3 rectangular surfaces , Let's calculate area for all of them:
2 similar right angled surfaces
We know that area of triangle =
⇒
⇒
⇒
But there 2 such surfaces so ,
3 rectangular surfaces
Area of rectangle =
⇒
⇒
⇒
⇒
⇒
⇒
Total area =
Adding area of 2 similar right angled surfaces & 3 rectangular surfaces:
=
Correct option B) .