It takes Mark 1 hour to get to work each day. Mark drives from home 20 minutes to the train station at a constant rate of 42 mph. He then takes the train, traveling at a constant 60 mph, the remaining distance to work. How far does Mark live from his work place? A. 108 mi. B. 80 mi. C. 62 mi. D. 54 mi. PLEASE HELP QUICK

D.54

Step-by-step explanation: it takes 20 minutes in the car which is 1/3 of an hr so 42/3= 14 then that leaves 40 minutes left for the train which is 2/3 of 60 and 60/3=20 and 20x2= 40 so 40+14=54

x =±sqrt(1/3)

step-by-step explanation:

x+4/6x=1/x

multiply each side by 6x to get rid of the fractions

6x*(x+4/6x)=1/x*6x

distribute

6x^2 +4 = 6

subtract 4 from each side

6x^2 +4-4 = 6-4

6x^2 =2

divide by 6

6x^2/6 = 2/6

x^2 = 1/3

take the square root of each side

sqrt(x^2) = ±sqrt(1/3)

x =±sqrt(1/3)

answer: 80,000

step-by-step explanation:

the population doubles every day.

10,000*2=20,000 day 4

20,000*2=40,000 day 5

40,000*2=80,000 day 6