2023 · Q8
If 2a/3 = 4b/5 = 3c/4, then what is the value of (18/a)√(a² + c² − b²)?
Elementary MathematicsRatio and Proportion
- A√35
- B√355
- C√375
- D√315
Explanation
2a/3=4b/5=3c/4=k gives a=3k/2, b=5k/4, c=4k/3. Then a^2+c^2-b^2=355k^2/144, sqrt=k sqrt(355)/12, and 18/a=12/k; product=sqrt(355). Option (b).