10 mL of a gaseous hydrocarbon was burnt completely in 80 mL of `O_(2)` at NTP. The remaining gas occupied 70 mL at NTP. This volume became 50 mL on treatment with KOH solution. What is the formula of the hydrocarbon?

Explanation

To solve the problem step by step, we will analyze the combustion of the hydrocarbon and the subsequent reactions that occur.

### Step 1: Write the combustion reaction of the hydrocarbon
Assume the hydrocarbon is represented as \( C_xH_y \). The balanced combustion reaction can be written as:
\[ C_xH_y + O_2 \rightarrow CO_2 + H_2O \]

### Step 2: Determine the volume of gases involved
Given:
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