13.15 ounces of 72% acid and 71.85 ounces of 25% acid are needed
<u>Step-by-step explanation:</u>
Total mass of acid required= 85 ounces
Let the mass of 72% acid be 'a'
Let the mass of 25% acid be 'b'
a + b = 85
b = 85-a
85(40/100) = a(72/100) + b(25/100)
85(2/5) = a(72/100) +(85- a) (25/100)
34 = (72a/100) + (2125/100) - (25a/100)
34 - (2125/100) = (72a + 25a) /100
(3400-2125)/100 = 97a /100
97a = 1275
a = 13.15 ounces
b = 85 - 13.14
b = 71.85 ounces
13.15 ounces of 72% acid and 71.85 ounces of 25% acid are needed
I had statistics in 10th grade
Answer:
1 1/15
Step-by-step explanation:
16/15
=1 1/15
......
....
..
.
Answer:
Answer
see explanation
Step-by-step explanation:
Using the rule of exponents
= , then
=
His mistake was in subtracting 3 rather than - 3
This question is incomplete because it was not written properly
Complete Question
A teacher gave his class two quizzes. 80% of the class passed the first quiz, but only 60% of the class passed both quizzes. What percent of those who passed the first one passed the second quiz? (2 points)
a) 20%
b) 40%
c) 60%
d) 75%
Answer:
d) 75%
Step-by-step explanation:
We would be solving this question using conditional probability.
Let us represent the percentage of those who passed the first quiz as A = 80%
and
Those who passed the first quiz as B = unknown
Those who passed the first and second quiz as A and B = 60%
The formula for conditional probability is given as
P(B|A) = P(A and B) / P(A)
Where,
P(B|A) = the percent of those who passed the first one passed the second
Hence,
P(B|A) = 60/80
= 0.75
In percent form, 0.75 × 100 = 75%
Therefore, from the calculations above, 75% of those who passed the first quiz to also passed the second quiz.
