Answer:
82 .
Step-by-step explanation:
9x 10 = 90 then 90-8 = 82 that how many spaces are filled .
1)
LHS:

LHS = RHS. So, the statement is true
2)
LHS:

LHS not equal to RHS. So, the statement is false
3)
LHS:

LHS = RHS. So, the statement is true.
4)
LHS:

LHS = RHS. So, the statement is true.
The first bag would be 5.34$ and the second would be 5.53$ and the second bag is better cause your only spending 19 more cents for 1.5 more pounds
If you are buying something that cost $15 and sale tax is 6%, you can calculate final bill trough proportions:
$15:100%=$x:106%
100x=106*15, x=(106*15)/100, x=$15.9 is final bill.
You can also use easier way: $15+0.06*$15=$15.9
Explanation for 2nd way: Cost is $15, on that you need to add 6% of $15: (6%/100%)*$15 and that is 0.06*15.