If 2.8, 7, 12 and x are in proportion then x = ……………….. A

1.	If 2.8, 7, 12 and x are in proportion then x = ……………….. A) 20 B) 31 C) 30 D) 40
Answer» Correct option is (C) 30 Given that 2.8, 7, 12 and x are in proportion. \(\therefore\) 2.8 : 7 = 12 : x \(\Rightarrow\) \(\frac{2.8}7=\frac{12}x\) \(\Rightarrow\) \(x=12\times\frac7{2.8}=\frac{12}{0.4}=\frac{120}4\) = 30 Correct option is C) 30

If 2.8, 7, 12 and x are in proportion then x = ……………….. A) 20 B) 31 C) 30 D) 40

Answer»

Correct option is (C) 30

Given that 2.8, 7, 12 and x are in proportion.

\(\therefore\) 2.8 : 7 = 12 : x

\(\Rightarrow\) \(\frac{2.8}7=\frac{12}x\)

\(\Rightarrow\) \(x=12\times\frac7{2.8}=\frac{12}{0.4}=\frac{120}4\) = 30

Correct option is C) 30