20/24, 30/36 & 40/48
5/6
10 × 2 / 12 × 2 = 20/24
10 × 3 / 12 × 3 = 30/36
10 × 4 / 12 × 4 = 40/48
10 ÷ 2/ 12 ÷ 2 = 5/6