Your classmate is starting a new fitness program. he is planning to ride his bicycle 30 minutes every day. he burns 7 calories per minute bicycling at 11 mph and 10.75 calories per minute bicycling at 15 mph. how long should he bicycle at each speed to burn 300 calories?

Aroulette wheel has 38 slots in which the ball can land. two of the slots are green, 18 are red, and 18 are black. the ball is equally likely to land in any slot. the roulette wheel is going to be spun twice, and the outcomes of the two spins are independent.the probability that it lands one time on red and another time on black in any order is(a) 0.5 (b) 0.25 (c) 0.4488 (d) 0.2244