15 13 28 24 54 52
15 × 1 – 2 = 13 13 × 2 + 2 = 28 28 × 1 – 2 = 26 26 × 2 + 2 = 54 54 × 1 – 2 = 52
28(4/5) + 52(1/2) × 8(2/7) - 11(1/5) = ? + 6(1/5)
(72 × 10 ÷ 20) × 10 = ?
115% of 40 + 3 × 4 = ? × 11 – 8
(115 × 17 × 3)/(23 × 51) + ?3 = √169
64.5% of 800 + 36.4% of 1500 = (?)² + 38
7, 8, 12, 21, 37, ?
(82 + 62 ) × 1.25 + 20% of 145 = ? – 40% of 65
464 + 181 +? = (154 × 25) - (15) 2
15% of 695 – 12.5% of 250 =? – 1200
(150% of 350) ÷ ? = 15
