If k = a c /b d = c e/d f = a e/b f when all quantities are positiv...
**Given Information:**
k = a c / b d
c e / d f = a e / b f
**To determine:**
Which of the following must be true:
(A) k = e / f
(B) k = c / d
(C) k = a / b
(D) All of the above
**Approach:**
We need to determine the relationship between k, a, b, c, d, e, and f based on the given information.
**Solution:**
Let's break down the given equations and analyze them separately.
1. k = a c / b d
2. c e / d f = a e / b f
**Analyzing the first equation:**
k = a c / b d
We can rewrite this equation as:
k b d = a c
This equation implies that k is directly proportional to a c, and inversely proportional to b d.
**Analyzing the second equation:**
c e / d f = a e / b f
Cross-multiplying this equation, we get:
c e * b f = d f * a e
This equation implies that c e b f is equal to d f a e.
Now, let's analyze the options:
(A) k = e / f
From the given equations, we cannot directly determine the relationship between k, e, and f. Therefore, option A cannot be determined to be true.
(B) k = c / d
From the given equations, we cannot directly determine the relationship between k, c, and d. Therefore, option B cannot be determined to be true.
(C) k = a / b
From the given equations, we know that k is directly proportional to a c and inversely proportional to b d. However, we cannot determine the exact relationship between k and a / b. Therefore, option C cannot be determined to be true.
(D) All of the above
Since we cannot determine the exact relationships between k and e / f, k and c / d, and k and a / b based on the given equations, option (D) cannot be true.
**Conclusion:**
None of the options provided (A, B, C, D) must be true based on the given information.
If k = a c /b d = c e/d f = a e/b f when all quantities are positiv...
D. all of the above
To make sure you are not studying endlessly, EduRev has designed CAT study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in CAT.