Answer: B - $27,500. It is very easy to quickly multiply 2-digit numbers by 11. For this problem, calculate 25 x 11, then add the 2 zeroes back at the end later.
Key Takeaway: To multiply a number by 11:
Rewrite the first number with a space between. In this case, 2 _ 5. Then, add those two numbers together (to get 7), and put that in the space: 275. Therefore, 25 x 11 is 275. Going back to the original problem, add the zeroes back at the end. 2500 x 11 = 27,500.
If the sum of the two digits is greater than 9, you will have to carry the 1. For instance, 48 x 11.
4_8
4+8 = 12.
Put the 2 in middle and carry the 1 and you will get 528.
