Question

The stock market has been really volatile the past two days. Yesterday, it rose by x% and today it fell by x%, resulting in an overall loss of 64%. What is x?

Answer 1

• 80

Explanation:

Let stock be s, then we get the equation below for the stock value:

• s(1 + 0.01x)(1 - 0.01x) = s(1 - 0.64)
• 1 - (0.01x)² = 0.036
• (0.01x)² = 0.64
• 0.01x = 0.8
• x = 0.8/0.01
• x = 80