Mr. Hoffman, a science teacher, drove 10 miles to school from home in 20 minutes. He drove the 2 miles home in 30 minutes. His average velocity was m/s.

In the first one he drove about 0.5 miles per second and in the second one he drove about 0.07 miles per second so it gives you about 0.285 i believe

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)

answer: a.

step-by-step explanation: the answer is a. because, you need to converge the fractions to find a solution.