The plane was in flight on the first day at 5 o’clock, and on the second-at 8 o’clock and flew all the time at the same speed.

The plane was in flight on the first day at 5 o’clock, and on the second-at 8 o’clock and flew all the time at the same speed. On the first day, the plane flew 1620 km less than on the second. How many kilometers did the plane fly on the first day?

Let’s denote the speed of the aircraft through x.

According to the condition of the problem, on the first day the plane was in flight for 5 hours, therefore, on the first day the plane flew a distance of 5 km.

It is also known that on the second day the plane was in flight for 8 hours, therefore, on the second day the plane flew a distance equal to 8x km.

According to the condition of the problem, on the first day the plane flew 1620 km less than on the second, therefore, we can draw up the following equation:

8x = 1620 + 5x.

We solve the resulting equation and find the aircraft speed:

8x – 5x = 1620;

3x = 1620;

x = 1620/3;

x = 540 km / h.

We find how many kilometers the plane flew on the first day:

5x = 5 * 540 = 2700 km.

Answer: on the first day, the plane flew 2,700 km.