Aaliyah looked at the clock and realized that her next class would begin in 27 minutes and end in 72 minutes. How many minutes long is
Aaliyah's next class?

Aaliyah's next class will be 45 minutes long.

Step-by-step explanation:

All you have to do to have the answer, is subtract the time her next class will start from the minutes that her class will end.

Subtract:

27 from 72 equals to 45. So 45 minutes is the answer.

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)