The problem describes a journey that takes place over three days. On the first day, 40% of the total distance is covered. On the second day, 1/5 of the total distance is covered. On the third day, 18 km is covered. The question asks what the total distance of the journey is.

1. Problem Description

The problem describes a journey that takes place over three days. On the first day, 40% of the total distance is covered. On the second day, 1/5 of the total distance is covered. On the third day, 18 km is covered. The question asks what the total distance of the journey is.

2. Solution Steps

Let the total distance be $x$ km.

On the first day, the distance covered is $40\%$ of $x$, which is $0.4x$.

On the second day, the distance covered is $\frac{1}{5}$ of $x$, which is $\frac{1}{5}x = 0.2x$.

On the third day, the distance covered is 18 km.

The sum of the distances covered each day equals the total distance. Thus,

$0.4x + 0.2x + 18 = x$

$0.6x + 18 = x$

$18 = x - 0.6x$

$18 = 0.4x$

$x = \frac{18}{0.4} = \frac{180}{4} = 45$

3. Final Answer

The total distance of the journey is 45 km.

The answer is C.