Travis is an avid skier. He is trying to decide whether to buy ski equipment. Typically, it costs him $60 a day to rent ski equipment and buy a lift ticket. You can buy ski equipment for about $400. A lift ticket alone costs $35 for one day. Find the break-even point. 4 days b. 11 days c. 6 days d. 16 days a. Please select the best answer from the choices provided

b) 1/3 * 1/5

step-by-step explanation:

each smallest part is 1/15 since the written one is 1/5 and it's divided by 3 equal parts. (1/5 )/3 = 1/15 = 1/3 * 1/5

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

source:  

the answer is  

d.

21

i did this one. so you should get it right.