Beginning at 8:30 A. M., tours of the National Capitol and the White House begin at a tour agency. Tours for the National Capitol leave every 15 minutes. Tours for the White House leave every 20 minutes. How often do the tours leave at the same time? A. Every 15 minutes
B. Every 30 minutes
C. Every 45 minutes
D. Every 60 minutes

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)

24

step-by-step explanation:

answer is 12345678900987654321234567890987654321

step-by-step explanation:

i think it might be a but you might want a second opinion