Skip to content

平成31年度 春期 ITパスポート試験 問34

This question's explanation and your answers so far.

問34
頻出度★★★

商品の販売数が700個のときの営業利益は表のとおりである。拡販のために販売単価を20%値下げしたところ, 販売数が20%増加した。このときの営業利益は何円か。 ここで, 商品1個当たりの変動費は変わらないものとする。 単位 円

項目金額
売上高700,000
費用変動費140,000
固定費300,000
営業利益260,000
出典 平成31年度 春期 ITパスポート試験 問34
解説

問 34

  • Incorrectア

    200,000 yen is close to the correct answer of 204,000 yen but is not equal to it. The correct calculation is Sales 672,000 − Variable cost 168,000 − Fixed cost 300,000 = 204,000 yen; there is no calculation path that yields 200,000 yen (it is a trap value that easily appears when a digit or the per-unit variable cost is miscalculated along the way).

  • イ

    正解 Operating profit is found by ‘Sales − Variable cost − Fixed cost’. First derive the unit price and the variable cost per unit from the original table. Unit price = Sales 700,000 ÷ 700 units = 1,000 yen; variable cost per unit = Variable cost 140,000 ÷ 700 units = 200 yen. After the price cut the unit price drops by 20% to 1,000 × 0.8 = 800 yen, and the sales volume rises by 20% to 700 × 1.2 = 840 units. The variable cost per unit stays at 200 yen, so the figures become: Sales = 800 × 840 = 672,000 yen; Variable cost = 200 × 840 = 168,000 yen; Fixed cost stays at 300,000 yen regardless of quantity. Therefore operating profit = 672,000 − 168,000 − 300,000 = 204,000 yen, so ‘イ’ is correct.

  • Incorrectウ

    260,000 yen is exactly the original operating profit before the price cut. It reflects the mistaken belief that a 20% price cut and a 20% volume increase offset each other and leave profit unchanged. In reality 0.8 × 1.2 = 0.96, so sales actually decrease (700,000 → 672,000 yen), and variable cost rises as the quantity grows (140,000 → 168,000 yen), so profit must end up lower than the original.

  • Incorrectエ

    320,000 yen is larger than the original profit of 260,000 yen, presupposing that profit increased. However, even though the unit price is cut by 20%, the sales volume rises by only 20%, so sales shrink to 0.96 times, and on top of that the variable cost increases; therefore operating profit can never exceed the original.

ここがポイント
  • Operating profit = Sales − Variable cost − Fixed cost. Grasp the nature of the costs: variable cost is fixed per unit and proportional to quantity, while fixed cost stays constant regardless of quantity.
  • When the unit price is −20% and the quantity is +20%, sales become 0.8 × 1.2 = 0.96 times (i.e., they decrease). The key point is not to jump to the conclusion that the two cancel out to zero.
用語

Your answers