+1(1st interchanges with last, 2nd with 2nd last and so on.)
64.889% of 399.879 + √? = 54.90% of 799.80 – 44.03% of 400.21
647.1 ÷ ? + 72.3 × 209.81 – 8743.1 = 6404
³√? `xx` 32.87 + 59.83 `xx` 28.7665 – 48.8745 `xx` 21.642 = 1085.344
? = 21.08 + 18.99 × 21.07
80.22 of 149.98% + 459.99 ÷ 23.18 = ?
(16.16 × 31.98) + 24.15% of 649.99 = ? + 124.34
(?)2 + 4.113 = 24.92 – 32.03
11.69% of 499.78 + (2.89 × 39.76) = ?
25, 28, 26, 29, 27, ?
