How many 4 digit numbers can you write if you can only use the digits 1 and 2?

Can someone me and plz do the problem

Koji is installing a rectangular window in an office building. the window is 823 feet wide and 534 feet high. the formula for the area of a rectangle is a=bh. what is the area of the window? enter your answer as a mixed number in simplest form in the box. $$ ft2

Asingle die is rolled twice. find the probability of rolling a 3 the first time and a 2 the second time