The average temperature for Monday, Tuesday and Wednesday is $$39^o$$​ C. The average for Tuesday, Wednesday and Thursday is $$42^o$$​C. If the temperature on Thursday is $$42^o$$​C, then what is temperature on Monday?

Correct option is B

Given:

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

Formula Used:

Average$$=\frac{\text{(Sum of numbers)}}{\text{(Total number)}}$$

Solution:

The average temperature for Monday, Tuesday, and Wednesday:

​$$\frac{M + T + W}{3} = 39$$​

M + T + W = 117

The average temperature for Tuesday, Wednesday, and Thursday:

​$$\frac{T + W + Th}{3} = 42$$​

T+ W+ Th=126

Given that the temperature on Thursday is 42°C,

Th=42

Substituting Th=42 in the second equation:

T + W + 42 = 126

T+W=84

Now, using the first equation:

M + 84 = 117

M=33

The temperature on Monday is 33°C.