What fraction is halfway between 9/10 and 10/10. question 8

Which operation should be performed first according to the order of operations? 44 • 2 – [(5 + 20 • 3) – 12] + 16 ÷ 2 5 + 20 20 • 3 16 ÷ 2 44 • 2

Based on what i know about mean, this doesn't add up.

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days