(Ex 6.2 #10) Singapore to Dhaka with 100 km/hr tailwind, max plane speed 900 km/hr. Time required satisfies...

• a$t \ge \frac{2900}{1000}$
• b$t \le \frac{2900}{1000}$
• c$t = \frac{2900}{900}$
• d$t > \frac{2900}{800}$