Ten pipes ar fitted to a tank. Some of these are filling pipes while the others are emptying pipes. Each filling pipe can fill the tank in 8 hours. Each of emptyting pipe can empty it in 16 hours . All the pipes are opened simultaneously. The tank takes 2 hours to be filled. How many filling pipes are fitted to it? Choose the correct answer from the following option.

Options

A. 8
B. 7
C. 9
D. 6

Explanation

To solve the problem step by step, let's denote the number of filling pipes as \( F \) and the number of emptying pipes as \( E \). Since there are a total of 10 pipes, we can express the number of emptying pipes as \( E = 10 - F \).

### Step 1: Determine the rates of filling and emptying
- Each filling pipe can fill the tank in 8 hours, so the rate of one filling pipe is:
\[ \text{Rate of one filling pipe} = \frac{1}{8} \text{ tank/hour} \]
Therefore, the rate of \( F \) filling pipes is:
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