A charity fair raised $6,000 by selling 500 lottery tickets. There were two types of lottery tickets: A tickets cost $10 each, and B tickets cost $60 each. How many tickets of each type were sold? 250, 250

So the equations are 10A + 60B = 6000 and A + B = 500

You could just solve those equations, but I would guess and check on a multiple choice test. 6000/500 = 12, which is so close to 10 that a large majority of the tickets sold were 'A' tickets. I

10 (480) + 60 (20) = 4800 + 1200 = 6000 Bingo.

480, 20 is the answer