Leo tolstoy was born on 9 sentyabrya year. "young loew has been in musclemania four years. in july 1837 suddenly his father died. (mother tolstoy died when he was two years old.) orphaned children moved to kazan, where she was their guardian, aunt p. i. yushkova. tolstoy lived in kazan six years. that was the time of his adolescence and youth. two and a half years he was preparing to enter the university. deciding to become a diplomat, tolstoy sat exams on the east branch. he successfully passed the exams on the history, geography, mathematics, statistics, russian literature, logic, english, french, german, latin, arabic, turkish and tatar languages. already in the time of leo tolstoy showed exceptional ability to learn foreign languages. later, the sister of the writer was talking about. professor hired as a senior teacher with whom tolstoy studied turkish and tatar languages, found his ability to master languages extraordinary."
Дано: v(собств.)=18 км/ч v(теч. реки)=2 км/ч t(по теч.)=1,5 часа t(по озеру)=45 минут = часов = ч (1 час = 60 минут) Найти: S=S(по теч.)+ S (по озеру) км Решение S(расстояние)=v(скорость)*t(время) 1) v(по теч.) = v(собств.) + v(теч. реки) = 18+2=20 (км/ч) - скорость катера по течению реки. 2) S (по теч.) =v(по теч.)*t(по теч.)=20*1,5=30 (км) - проплыл катер по течению реки. 3) S(по озеру) = v(собств.)*t(по озеру) = 18* = = 13,5 (км) - проплыл катер по озеру (стоячая вода, поэтому берется только собственная скорость катера). 4) 30+13,5=43,5 (км) - проплыл катер всего. ответ: 43,5 км
часов = 
ч (1 час = 60 минут)
= 13,5 (км) - проплыл катер по озеру (стоячая вода, поэтому берется только собственная скорость катера).
х га - 7%
х=(25,3*7)/100=1,771 га
2. 20 - 100%
3,8 - х %
х=(3,8*100)/20=19%