In order to answer the question, you need to know what a multiple is. A multiple is a number which can be divided by the original number without a remainder. So for example multiples of 5 include: 5, 10, 15, 20, 25, etc... you are basically adding 5 each time. So in this question, you are being asked to list what the multiples of 9 are that are less than 80. You begin by listing the multiples of 9 and stop once you get to 80.
9,18, 27, 36, 45, 54, 63, 72, 81. You stop here because the last multiple of 9 that you listed is more than 80. So your answer to this question would be: 9,18, 27, 36, 45, 54, 63, 72.
If a map is being reduced to form a pocket sized version then it is being proportionality reduced a smaller size that is required. Cartographers enlarge and reduce maps proportionally to serve different purposes in their study. The map is still the same but smaller in size.
If on a map 2cm represents 2 meters, that is 0.02/2 which evaluates to 1/100, then we are comparing distance and ensuring they are proportional using scale factor(our scale factor is 1:100 here)
In order to find this, notice that the price of the sale represents 80% of the total cost. This is because we took 20% away with the sale. Now we can find the overall amount by dividing the sale cost by the amount it represents.
