По плану должны были построить 750 квартир, а построили 855. Сколько процентов плана было выполнено?

Найдите силу притяжения двух тел массами по 20кг, находящимися на расстоянии 10м

1. СРОЧНО!!!!
2.   Insert the verb in the right tense form (The Present Perfect tense or the Past Simple Tense.
3. I (to write) my first program for a computer when I (to be) thirteen years old.
4. It (to change) our lives and it is changing them again, because now the computers are coming together to make a new system.
5. I'm very happy that I will be a part of this strange new time. I (to feel) this happiness and excitement before.
6. One day in 1972, when I (to be) sixteen and he was nineteen, he (to show) me something that he was reading.
7. After I (to write) that first program at the age of thirteen, my friend Paul Allen and I (to spend) a lot of time using computers.