Answer: The answer is 10.
Explanation:
These steps will help you!
STEP 1: You need to multiply them and use the process of elimination.
8 is obiviously too little.
9 is still too little.
10 when you multiply it with $1.78, it's simple enough that it equals just right!
11 is too over.
STEP 2: Try multiplying 1.78 x 10.
1.78
x 10
0
+ 1 7 8 0 _______always add the 0.
$ 1 7 . 8 0
Mark also has $1.20 left to spare.
STEP 3: Declare the answer!
Mark can buy 10 stamp packets and have $1.20 left for himself.
Hope this helps!