Tom runs a marathon (26.2 miles) in 4 hours and 12 minutes. how many miles per hour does he run? . without calculating the answer, from the choices given, which is most reasonable? . a. 12 kilometers per hour. b. 6 miles per hour. c. 3 miles per hour. d. 20 miles per hour.

The correct answer to this question is letter "B. 6 miles per hour." 

distance = rate * time

26.2 = rate*4 hours and 12 minutes

(convert 4 hours and 12 minutes to hours)

= 4.2 hours

rate = 26.2 / 4.2

rate = 6.23

c. 4 1/4 pounds

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)