X=number of gallons that she must order.
4 gallons-----------------3 weeks
(7 gallons + x)--------12 weeks
We solve this rule of 3.
(7 gallons +x)3 weeks=4 gallons*12 weeks
21 gallons weeks+3 x weeks=48 gallons weeks
3x weeks=48 gallons weeks - 21 gallons weeks
3x weeks=27 gallons weeks
x=(27 gallons weeks) / 3 weeks=9 gallons.
Solution: she must order 9 gallons more.
Answer:

Step-by-step explanation:
3 envelopes having 2 red card
2 envelopes having 1 red card and 1 black card
1 envelope having 2 black cards
We are given that . An envelope is selected at random and a card is withdrawn and found to be red.
So, No. of ways of envelope having red card = 3+2 = 5
No. of required ways of envelope having 1 red card and 1 black card = 2
So, probability of getting an envelope having 1 red card and 1 black card = 
Hence The chance the other card is black is 
To check if this point lies on the line, plug in a 2 for x and a y for 1 and solve
x+2y=5
2+2(1)=5
4=5
Since this statement isn't true, then the point doesn't lie on the line
Hope this helps
The answer is 9/42. might be wrong I'm rusty on this.
Hello, the answer for your question is<span> 12.7.</span>