Am I correct or not? if not, please tell me the answer

How has apple been able to sustain its competitive advantage in the smartphone industry? a. by reducing its network effects b. by targeting its new products and services toward laggards c. by driving the price for the end user to zero d. by regularly introducing incremental improvements in its products

You wish to retire in 13 years, at which time you want to have accumulated enough money to receive an annual annuity of $23,000 for 18 years after retirement. during the period before retirement you can earn 9 percent annually, while after retirement you can earn 11 percent on your money. what annual contributions to the retirement fund will allow you to receive the $23,000 annuity? use appendix c and appendix d for an approximate answer, but calculate your final answer using the formula and financial calculator methods.

Luggage world buys briefcases with an invoice date of september 28. the terms of sale are 2/10 eom. what is the net date for this invoice