13. Check the following combinations of puts and calls and determine whether they conform to the putcall parity rule for European options. If you see any violations, suggest a strategy.

a. July 155

b. August 160

c. October 170

14. Repeat problem 13 using American putcall parity, but do not suggest a strategy.

The following option prices were observed for a stock on July 6 of a particular year. Use this information to solve problems 11 through 16. Unless otherwise indicated, ignore dividends on the stock. The stock is priced at 165.13. The expirations are July 17, August 21, and October 16. The risk-free rates are 0.0516, 0.0550, and 0.0588, respectively. CALLS PUTS 155 STRIKE JUL AUG OCT JUL AUG OCT 10.50 11.80 14.00 0.20 1.25 2.75 160 6.00 8.10 11.10 0.75 2.75 4.50 2.70 5.20 8.10 2.35 4.70 6.70 170 0.80 3.20 6.00 5.80 7.50 9.00 165 The following option prices were observed for a stock on July 6 of a particular year. Use this information to solve problems 11 through 16. Unless otherwise indicated, ignore dividends on the stock. The stock is priced at 165.13. The expirations are July 17, August 21, and October 16. The risk-free rates are 0.0516, 0.0550, and 0.0588, respectively. CALLS PUTS 155 STRIKE JUL AUG OCT JUL AUG OCT 10.50 11.80 14.00 0.20 1.25 2.75 160 6.00 8.10 11.10 0.75 2.75 4.50 2.70 5.20 8.10 2.35 4.70 6.70 170 0.80 3.20 6.00 5.80 7.50 9.00 165