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?

Answer 1

a + b = 500
10 a + 60 b = 6000 divide this by ten

a + b = 500
a + 6 b = 600
------------ subtract
-5 b = -100

b = 20
so a = 480

check
480*10 + 20 *60 = 4800 +1200 = 6000 sure enough