Correct Answer - Option 4 : 39°C
Given:
The average temperature on Monday, Tuesday and Wednesday = 40°C
Temperature of Tuesday, Wednesday and Thursday = 41°C
Temperature of Thursday = 42°C
Formula used:
Mean = Sum of no. observation/No. of observation
Calculation:
Average temperature for Monday, Tuesday and Wednesday = 40°C
Total temperature = 3 × 40 = 120°C
Average temperature for Tuesday, Wednesday and Thursday = 41°C
Total temperature = 41 × 3 = 123°C
Temperature on Thursday = 42°C
⇒ (Tuesday + Wednesday + Thursday) - (Monday + Tuesday + Wednesday) = 123° - 120°
Thursday - Monday = 3°
Monday = 42° - 3° = 39°C
∴ The temperature on Monday is 39°C.