Chapter 11.1, Problem 29PPS

To determine

To Find: To find the number of pints used.

Answer to Problem 29PPS

The answer is 3.

Explanation of Solution

Given information: Given Sides of roof and tower

Formula used: Area of triangle $=\frac{1}{2}\times \text{base}\times \text{height}$ and area of rectangle $=\text{length}\times \text{breadth}$

Calculation:

Since the height of the roof is 6feet and base is 5 feet

Therefore, area of roof is

  $\begin{array}{l}=\frac{1}{2}\times 5\times 6\\ =15\end{array}$

Thus, area of roof is 15square feet.

Also, area of tower is

  $\begin{array}{l}=5\times 12\\ =60\end{array}$

Thus, area of tower is 60square feet.

Now, the total area paint in one coat is 75 square feet

Therefore, paint used in 3 coats is

  $\begin{array}{l}3\times 75\\ =225\end{array}$

And, one pint covers 80 square feet pain

So, number of pints used is

  $\begin{array}{l}=\frac{225}{80}\\ =2.8125\end{array}$

Which is approximately 3

Hence 3 pints are needed.