Try this option:
1. rule: P(E)+P(not E)=1.
2. according to the rule above
P(not E)=1-P(E)=1-0.3=0.7;
P(E)=1-P(not E)=(100-65)%=35%.
To set up this equation you create 14x+12y=314 is equal to 7x+11y-247 (the x representing the number of blue berries, and y representing the number if blackberry pies. In the end.
Multiply 0.27 by 100. It will equal 27. Then subtract 27 from 100. The answer is 73%
The equation should have been written as 1.25x+1.49y=100.
The error made in the first equation was that Barbara did not include a variable next to the term 1.49. Since the ice tea is sold for $1.49 per bottle, a variable should be included to represent however many bottles of iced tea she sold.