A new phone sells for $250 and a used one sells for $75. How many of each are sold if the profit for the day is $625?

Answer:1 new and 5 usedStep-by-step explanation:If we subtract multiples of 250 from 625 and divide by 75, we can determine the number of phones.  We know that 250(2) = 500; if we subtract this from 625, this leaves 625-500 = 125 for the old phones.  Dividing this by 75, we see that it is not a whole number; this means there cannot have been two of the new $250 phones sold.625-250 = 375.  Dividing this by 75, we get 5; this means 1 new phone and 5 old were sold.