Numbers like 10,100,1000 are called?

Which choice represents the sample space ,s for this event

Your client has saved $1,860 for a down payment on a house. a government loan program requires a down payment equal to 3% of the loan amount. what is the largest loan amount that your client could receive with this program

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers