Make a set of numbers that use all the digits from 1 to 9, once and once only.

1, 2, 3, 4, 5, 6, 7, 8, 9.

there will be 362880 numbers that use all the numbers from 1 to 9 only once

Step-by-step explanation:

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)