The four-firm concentration ratio is the percentage of the value of sales accounted for by the four largest firms in the industry. A ratio of 0 percent: indication of perfect competition.
14 × 11 + 25 – ? = 21% of 300
30 of 20 - 40 + 182 - 23 × ? = 83
45% of 360 - 160 + ? = √324
∛857375 + ∛91125 = ? + √6889
?% of 140 + 16% of 250 = 62 × 12
25% of {(5/18) × 2880 + 122 } = ?% of 590
654.056 + 28.9015 × 44.851 – 43.129 = ?
135÷ 15 x 19 + 14807 = ? + √3249 - √9604
{(8× 8 + 3 × 39) - 620 ÷ 20} = ?
(√121 + √196) × 7 =? × 5
