Which of these equations represent the table of values

For what values of b will f(x)= logbx be a decreasing function? (16 )

If a baby uses 15 diapers in 2 days how many diapers will the baby use in a year

Scrub a dub toothbrushes are $4.00 each. there is a 10% discount, but there is also a 6% sales tax after the discount is applied. what is the new price after tax? round to the nearest penny