Answer:
Since, there are 21 blue marbles for every 4 white marbles, therefore the ratio of blue marble to white marbles is 21:4.
Step-by-step explanation:
First find the probability of each color being drawn.
We need to find the total number of marbles first.
4 + 3 + 6 = 13
So everything will be over 13.
Probability of a white marble being drawn --> 
Probability of a blue marble being drawn --> 
Probability of a red marble being drawn --> 
Now to find the probabilities of more than one being drawn, we can multiply.
Part a :

Part b :

Part c :

Part d :

Answer:
$8.75
Step-by-step explanation:
Tiffany allowance is reduced by $1.25 each time she forgets to clean her room
If she forgets to clean her room 7 times this month
Then her allowance is reduced by
= 1.25 × 7
= 8.75
Hence Tifanny allowance is reduced by $8.75