Answer: C
Let, 2a=3b=4c=k
Thus, a=\(\cfrac{k}{2}\),b=\(\cfrac{k}{3}\) এবং c=\(\cfrac{k}{4}\)
Therefore, 2a:5b:7c=\(\cfrac{2k}{2}\):\(\cfrac{5k}{3}\):\(\cfrac{7k}{4}\)
=\(1: \cfrac{5}{3}\):\(\cfrac{7}{4}\)
Multiplying by 12 to remove the fractions:
=\(\cfrac{2×12}{2}\):\(\cfrac{5×12}{3}\):\(\cfrac{7×12}{4}\)
=12:20:21
Let, 2a=3b=4c=k
Thus, a=\(\cfrac{k}{2}\),b=\(\cfrac{k}{3}\) এবং c=\(\cfrac{k}{4}\)
Therefore, 2a:5b:7c=\(\cfrac{2k}{2}\):\(\cfrac{5k}{3}\):\(\cfrac{7k}{4}\)
=\(1: \cfrac{5}{3}\):\(\cfrac{7}{4}\)
Multiplying by 12 to remove the fractions:
=\(\cfrac{2×12}{2}\):\(\cfrac{5×12}{3}\):\(\cfrac{7×12}{4}\)
=12:20:21