Question

Two temperature scales $A$ and $B$ are related by $\frac{A-42}{110}=\frac{B-72}{220}$. At which temperature tow scales have the same reading?

• A. $-{42}^o$
• B. $-{72}^o$
• C. $+{12}^o$
• D. $-{40}^o$

Answer 1

Answer: (C)

$+{12}^o$

The relation between two temperature scale is given as:

$\frac{A-42}{110}=\frac{B-72}{220}$

For the two temperature scale to show same reading, $A=B$

$\Rightarrow \frac{A-42}{110}=\frac{A-72}{220}$

$\Rightarrow 2(A-42)=A-72$

$\Rightarrow 2A-84=A-72$

$\Rightarrow A=+{12}^0$