Answer: The answer is B or 2.
Step-by-step explanation:
We use the formule: t=S/v. So:
+ t1= 160/100 = 8/5 hrs = 5760''
+ t2= 160/90 = 16/9 hrs = 6400''
=> t2-t1= 6400 - 5760 = 640'' = 10'40''
We can use trigonometry. The cosine of 15 will be the side adjacent to the 15-degree side (the one we are looking for) divided by 20, the hypotenuse. As cos(15) is about .966, we get 19.32 as the side we are looking for.
