Answer:
Total Contribution margin:   107,500,000
Explanation:
<u>Contribution:</u> sales revenue - variable cost
normal price 5,000
peak-load price: 5,000 + 20% = 5,000 x 1.2 = 6,000
<u>revenue</u>
20,000 units  at 5,000   100,000,000
  5,000 untis  at 6,000 <u>    30,000,000  </u>
              Total revenue      130,000,000
<u>variable cost:</u>
25,000 units x 900 =         (22,500,000)
Total Contribution margin:   107,500,000