Question 26828
When something is enlarged 30%, it becomes 30% larger than its original size (100%) or 130% times the original size. It's slightly confusing wording, but you should realize that something that's being enlarged by 30% isn't the same thing as multiplied by 30% because that would be a reduction. For instance, if you increased a picture's length that was 10" by 30% and accidentally only multiplied by 30% instead you'd end up with an "enlarged" length of 3" Obviously this needs to be added to the original length so the answer is:
{{{10 + .30(10) = 10 + 3 = 13 = 1.3(10)}}}
It may help when given these types of problems, to create a dummy length (I used 10", but anything would work). For your problem, we're preforming the enlargement twice. It is not enough to simply add them together to get .6. You can prove this quickly by taking our dummy value of 10" and multiplying it by .6 to get 6"  This is clearly not an enlargement.
What should you have done instead? First realize that the enlargement is 1.3 times, not .3. Also, you cannot simply add the two enlargements and get 2.6 (another fake answer). These two values must be multiplied together to get 1.69 or ~ 1.7 (1). Why? Well, again, let's go to our fake value example...

If we start with 10" and apply 1 enlargement of 30% we got:
{{{10 * 1.3= 13}}} 
When you apply it again, you apply it to the enlarged value of 13" to get:
{{{13 * 1.3= 16.9}}} To find the total enlargement, we divide our final value 16.9" by our original value 10" and get our answer of:
{{{16.9/10=1.69}}} or approximately 1.7