Answer:
Step-by-step explanation:
26% is (26-20)/(50-20) = 6/30 = 1/5 of the way between 20% and 50%. That means 1/5 of the solution is 50% acid.
50% acid: 1/5 · 100 mL = 20 mL
20% acid: 100 mL -20 mL = 80 mL
Delbert must mix 80 mL of 20% acid and 20 mL of 50% acid.
_____
Maybe you'd like to see an equation. Let x represent the amount of 50% acid required. Then 100-x is the amount of 20% acid needed. The amount of acid in the mix is ...
0.50(x) +0.20(100 -x) = 0.26(100)
(0.50 -0.20)x = (0.26 -0.20)100 . . . . subtract 0.20(100)
x = (0.26 -0.20)/(0.50 -0.20)×100 = 20
This last expression should look a lot like the one we started with in this answer. It shows you how you can almost write down the answer to mixture problems without a lot of work.
Answer:
Step-by-step explanation:
M=9-R is the equation for it
The answer is C. 68/5 - 54/5i
Answer:
Table C is the correct option.
Step-by-step explanation:
We are given,
Number of students which knew French = 57
Number of students which knew both French and Spanish = 23
Number of students which knew Spanish but not French = 11
Number of students which knew neither French nor Spanish = 4
So, we get that,
Number of students not knowing French = 57 - 23 = 34
Hence, the table for the given situation is,
Knew Spanish Did not know Spanish Total
Knew French 23 34 57
Did not know French 11 4 15
Total 34 38 72
Thus, option C is correct.
