70 percent off 60

70% off 60 is 18

60 minus 70 percent off is 18

The discount itself is 42: 60 × 70 ÷ 100 = 42. Taking it off 60 leaves 18.

Only approximately: 18 ÷ 0.3 = 60. The discount is rounded to the cent, so several prices give the same 18 — 59.99 (discount 41.99), 60 (discount 42) and 60.01 (discount 42.01); the paid price alone cannot tell them apart.