Question

The average temperature of Monday to Wednesday was ${37}^{\circ }C$, and of Tuesday to Thursday was ${34}^{\circ }C$. If the temperature on Thursday was $\frac{4}{5}$ that of Monday, what was the temperature on Thursday?

• A. ${36}^{\circ }C$
• B. ${46}^{\circ }C$
• C. ${56}^{\circ }C$
• D. ${66}^{\circ }C$

Answer 1

Answer: (A)

${36}^{\circ }C$

Let the temperatures on Monday, Tuesday, Wednesday and Thursday be $M,T,W$ and $Th$ respectively.

Then $M+T+W=3\times {37}^0$ C $={111}^0$ C .....(i)

$T+W+Th=3\times$ ${34}^{\circ }$ C $={102}^{\circ }$ C ........(ii)
Doing Eq (i) $-$ Eq (ii)

$\Rightarrow$ $M-Th=$ ${111}^{\circ }C-{102}^{\circ }C=9^{\circ }C$
Also given $Th=\frac{4}{5}M$

$\Rightarrow M-\frac{4}{5}M=9$

$\Rightarrow M={40}^{\circ }C$
Therefore, temperature on Thursday $=\frac{4}{5}\times {45}^{\circ }C={36}^{\circ }C$