MATHS AS PLAYCOMENIUS 2011 – 2013

MATHS AND OTHER SUBJECTS

March 2013

Maths and Nature-studyProblem 1: The pike, which lives up to 200 years, is a long-lived fish. The trout can live 10 times less and the eel – 35 years more than the trout.

a) How long can the trout live?b) And what about the eel?

Problem 2: An ostrich lays about 15 eggs for a year. It’s 12 times less than a hen. A hen egg weighs about 50 g and it’s approximately 30 times lighter than an ostrich one.

a) How many eggs can a hen lay for a year?b) How heavy is an ostrich egg?c) How many grams is it heavier than a hen egg?

Problem 3: The pulse of an elephant is at 30, and the pulse of a human is at 65-70 per minute.

a) How many times does an elephant’s heart beat for an hour?

b) What about the human heart?c) During one contraction the human heart shoves

out about 85 g of blood. How much blood will it shove out for an hour? (kilograms or grams)

Maths and History

Problem 1: Now the year is 2013. How many years ago:

- was the proclamation of the Bulgarian state if it happened in 681?

- was the first school in Gabrovo founded if it happened in 1835?

- was the first Bulgarian book printed if it appeared in 1651?

Problem 2: Here are some important dates in the history of Bulgaria. Determine what centuries are they in and mark them on the timeline.

I----------I----------I----------I----------I----------I--------› VII c VIII c IX c X c XI c

1) 681 – Proclamation of the Bulgarian state2) 864 – Bulgarian people became converted to Christianity3) 917 – Simeon, the Bulgarian tsar, defeated the Byzantine army4) 1018 – The Byzantine army conquered Ohrid

Maths and Geography

Problem 1: The River Volga is 3,530 km long which is 838 km longer than the Danube and 2,983 km shorter than the Nile in Africa.

a) How long is the Danube?b) How long is the Nile?

Problem 2: In 1985 the population of the Earth was 5 billion people. 300 years before that it was only 545 million. a) How many people did the population increase with during this period?Presumably in 2025 the population will be 8 600 000 000 people.b) How many people on the average is the population increasing with every year during the period 1985-2025?

Problem 3: The distance between two objects on the map is 7 cm. What is the real distance if the scale is of one to ten million?a) 7 kmb) 70 kmc) 700 kmd) 7 000 km

Problem 4: Calculate the population density of Bulgaria if the population is 7 364 570 people and the territory of the country is 110 879 km².

Good luck!