Question

Carol Ann buys a TV at 70% off the original price. If she pays $120, what was the original price of the TV?

Answer 1

If the TV is 70% off, then that means she paid 30% of the original cost.  If 30% of the original cost  is $120, then...

30% * x = 120
.30x = 120
x = 120/.30
x = 400

The original cost was $400

Answer 2

Original price x (100-70)/100 = $120

therefore; original price = 120 × 100/30 = $400