A pedestrian walks at a speed of 4 km / h. How many kilometers a pedestrian will walk in 30 minutes.

Let us determine, by making a proportion, what distance a pedestrian will cover in 30 minutes, if his speed is 4 km / h, 1 hour will be designated as 60 minutes:
4 km = 60 min,
x km = 30 min.
Let’s write the equation, acting according to the “cross” rule and find the value of the variable:
x = 4 * 30: 60 = 120: 60 = 2 km.