How to say "Mathematical Olympiad" in English?

How to say "Mathematical Olympiad" in English?

Mathematical Olympiad
International Mathematical Olympiads is called IMO for short

A freight car departs from a place to B at 6 am, traveling 45 kilometers per hour on average. A passenger car departs from B place to a place, 15 kilometers faster than the freight car on average. It is known that the passenger car departs 2 hours later than the freight car. At 12 noon, the two cars pass a station on the way at the same time, and then continue to move forward. When the passenger car arrives at a place, how many kilometers is the freight car from B place?

① Bus speed: 45 + 15 = 60 (km); ② distance between two places: 45 × (12-6) + 60 × (12-6-2), = 45 × 6 + 60 × 4, = 510 (km); ③ time for bus to complete the whole journey: 510 ／ 60 = 8.5 (H); ④ distance between bus and B when bus arrives at a place: 510-45 × (8.5 + 2), =

The speed of a sailing boat is 60 m / min. in the river with a current speed of 20 m / min, it takes 3 hours and 30 minutes for the boat to go from a port in the upstream to a place in the downstream and then return to the original place. How many meters has the boat gone from the port in the upstream to a place in the downstream?

3 hours and 30 minutes = 312 hours. 80 × (312 × 11 + 2 × 60), = 80 × 70, = 5600 meters. A: the ship has traveled 5600 meters from the upstream port to a certain place downstream

A and B horses set out at the same time at a distance of 70 meters. When they set out, a horse was in front and B horse was behind. If a horse ran 8 meters per second and B horse ran 14 meters per second, how many seconds later did B horse exceed a horse by 50 meters?

(70 + 50) △ 14-8, = 120 △ 6, = 20 (seconds), a: after 20 seconds, the second horse is 50 meters more than the first horse