5th Grade Math in the Ukrainian school

I know, it all looks foreign to you, my American friends and family :)  This is a picture from the Math textbook in the 5th grade in Ukraine, and... it's from the same school I went to! The school with toughest teachers in town, toughest classmates and classes, which are mandatory, by the way. If you don't like physics or a foreign language class, too bad. You are REQUIRED to take it AND get a good grade. End of story.

So, let's look at these problems.
575. How are K,M and N dots situated, if:
        a) KM = 23 cm, MN = 75 cm, KN = 57 cm;
        b) KM = 49 cm, MN = 37 cm, KN = 86 cm?

576. a) A merchant "Monkey" (he-he!) purchased 2 kinds of candy totaling 6,570 rubels, 40 kg of which at 96 rubels per 1 kg, and the rest is at 78 rubels per kg. How much of cheaper candy did they buy?
        b) "Oka" driver passed a cop at 105 km/h speed without stopping. 2 minutes later the upset cop was chasing him on BMW bike (he-he) at a speed of 210 km/h, and didn't notice that he had passed the "Oka" driver. 10 minutes later after the passing, he realized his mistake, turned around, and started driving towards the driver at a reduced speed of 45 km/h. How long after the U-turn did it take the cop to meet with the "Oka" driver?

577. Calculate:
        a) 395 x 52 - 603 x 25 - 960 / 24;       b) 256 x 407 - 33,078 / 298

578. Calculate:
        a) 3/16 + 5/16;    b) 11/15 - 8/15;    c) 23/25 - 18/25;     d) 15/28 + 9/28

To me, the 576 b) is the hardest... See if you can figure them all out. The answers are coming in one of the next posts :)