Характеристика Андрия Бульбы

1 задача

Сколько решений имеет система

{ x1+x2+x3+x4+x5=38

x1+ x2 =x3+x4+x5

а) в целых неотрицательных числах;

б) в целых положительных числах;

2 задача

найти число целых положительных чисел, не превосвохдящих 210, не делящих ни на 9, ни на 12, ни на 15.

3 задача

Сколько существует перестановка чисел 1, 2,3,...n, в которых ровно два элемента стоят на своих исходных местах?

Помогите написать письмо-ответ на английском языке.

you have received a letter from your english-speaking friend Cole who writes:

This month we have completed a course of outward bound activities we've been up to the mountains on a hiking tour. We spent an unforgettable time there, exploring the beautiful scenery and doing different challenging tasks. And what area of your country would you like to know better? How will you explore it? Who would you prefer to go with? I'm going to take gap year after graduating, and, unfortunately, I haven't got a scholarship.

In your letter:

answer her questions

ask 3 questions about his plans for spending his gap year

write 100-140 words