2022 · Q70
The length of a room is (21)/(16) times its breadth and breadth is (4)/(3) times its height. If H is the height of the room and L is the longest rod that can be placed in the room, then which one of the following is correct?
Elementary MathematicsMensuration
- A12L = 29H
- B9L = 25H
- C7L = 23H
- D5L = 13H
Explanation
b = 4H/3 and l = 21b/16 = 7H/4. Then L = √(l²+b²+H²) = H√(49/16+16/9+1) = H√(841/144) = 29H/12, so 12L = 29H. The keyed option is A.