Solve the problem.
mark can remember only the first 4 digits of his friend's phone number. he also knows that the number has 7 digits and that the last digit is not a 0. if mark were to dial all of the possible numbers and if it takes him 21 seconds to try each one, how long would it take to try every possibility?

In the diagram, the measure of angle 9 is 85° which angle must also measure 85°?

The avenues in a particular city run north to south and are numbered consecutively with 1st avenue at the western border of the city. the streets in the city run east to west and are numbered consecutively with 1st street at the southern border of the city. for a festival, the city is not allowing cars to park in a rectangular region bordered by 5th avenue to the west. 9th avenue to the east, 4th street to the south, and 6th street to the north. if x is the avenue number and yis the street number, which of the following systems describes the region in which cars are not allowed to park? 5th ave 9th ave

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?