Most of the examples in this section use the following premiums,which are based on the Black-Scholes formula for a stock currently selling at $100, a 6-month expiration date, a 4% effective rate for a 1/2 year period and no stock dividends.
Strike price = $90, 100, 110
Call = $16.36, 10.35, 6.11
Put = $2.90, 6.50, 11.88
Question: For what spot price at expiration would the profit be the same under (1) and (2), where (1) is a 90-100-110 butterfly spread and (2) is a written straddle