Answer:
19. 16%
21. C
Explanation:
19.
To solve 19, add all the 'number' in the table. You should get 75. After that, divide by 12 because that's the yellow marble and to find the percentage, divide 12 by 75. 0.16. Now multiply by 100 because 0.16 is how you write percentages in expressions and equations (Math sentence) So, the answer is 16%.
21.
The initial value is a one-time addition. The one-time addition is 10.45. The rate is 5, because it's constantly changing by 5. So, 70.45-10.45 is 60. Divide by 12 (months) and you'll get 5. So, the answer for 21 is C.