Answer:
a) 8
b) 12
Step-by-step explanation:
With orange: 2×2×2 = 8
With yellow: 2×2 = 4
Total = 8+4 = 12
The top 15% (85th percentile) is the cutoff value

such that

where

is the corresponding cutoff for the standardized normal distribution. We have

, and so
Counting in 10s is faster than counting in ones because counting in 10s gets you to larger numbers faster because you are going by larger numbers.