A:B=2:3, B:C=5:8, C:D=6:7 হলে A:D= কত ? (a) 2:7 (b) 7:2 (c) 5:8 (d) 5:14 Madhyamik 2022
Answer: D
\(∵ A:B=2:3\)
বা, \(\cfrac{A}{B} = \cfrac{2}{3}\)
একইভাবে, \(\cfrac{B}{C}=\cfrac{5}{8}\)
এবং \(\cfrac{C}{D}=\cfrac{6}{7}\)
\(∴ \cfrac{A}{B}×\cfrac{B}{C}×\cfrac{C}{D} = \cfrac{\cancel2}{\cancel3}×\cfrac{5}{\cancel{8}\cancel{4}2}×\cfrac{\cancel{6}\cancel2}{7}\)
বা, \(\cfrac{A}{D}=\cfrac{5}{14}\)
\(∴A:D=5:14\) (Answer)
\(∵ A:B=2:3\)
বা, \(\cfrac{A}{B} = \cfrac{2}{3}\)
একইভাবে, \(\cfrac{B}{C}=\cfrac{5}{8}\)
এবং \(\cfrac{C}{D}=\cfrac{6}{7}\)
\(∴ \cfrac{A}{B}×\cfrac{B}{C}×\cfrac{C}{D} = \cfrac{\cancel2}{\cancel3}×\cfrac{5}{\cancel{8}\cancel{4}2}×\cfrac{\cancel{6}\cancel2}{7}\)
বা, \(\cfrac{A}{D}=\cfrac{5}{14}\)
\(∴A:D=5:14\) (Answer)