Step-by-step explanation:
Let's denote:
- \( L \) as the number of people who wanted the library only,
- \( P \) as the number of people who wanted the park only,
- \( B \) as the number of people who wanted both,
- \( N \) as the number of people who did not want either the library or the park.
From the given information, we can write the following equations:
1. Total number of people surveyed: \( L + P + B + N = 120 \)
2. Number of people who wanted the library is one-third of the number of people who wanted the park: \( L = \frac{1}{3}P \)
3. Number of people who wanted both: \( B = 22 \)
4. Number of people who did not want either: \( N = 22 \)
To find the number of people who wanted the park only, we can use the equation:
\[ P = \frac{120 - (22 + 22)}{4} = \frac{76}{4} = 19 \]
Now, to find the total number of books collected if everyone contributes 15 books each for the library:
\[ \text{Total number of books} = L \times 15 = \frac{1}{3}P \times 15 \]
Substituting \( P = 19 \) from the previous calculation:
\[ \text{Total number of books} = \frac{1}{3} \times 19 \times 15 = 95 \]
So, a total of 95 books will be collected if everyone who wants to build a library contributes 15 books each.