Mean temperature of a city of a certain week was 25°C. If the mean temperature of Monday, Tuesday, Wednesday and Thursday was 23°C and that of Thursday, Friday, Saturday and Sunday was 28°, find the temperature of Thursday.
Answers
The answer is 34 .............
Thursday's temperature = 29°C.
Explanation:
Mean temperature of a city of a certain week was 25°C.
Mean temperature of Monday, Tuesday, Wednesday and Thursday was 23°C
Mean of Thursday, Friday, Saturday and Sunday was 28°
Mean temperature of week = 25°C.
( Sunday + Monday + Tuesday + Wednesday + Thursday + Friday + Saturday ) / 7 = 25
( Sunday + Monday + Tuesday + Wednesday + Thursday + Friday + Saturday ) = 175 --------(1)
Given (Monday + Tuesday + Wednesday + Thursday ) / 4 = 23
(Monday + Tuesday + Wednesday + Thursday ) = 92
Substituting this in equation (1), we get:
( Sunday + 92 + Friday + Saturday ) = 175 ---------(2)
Given ( Thursday + Friday + Saturday + Sunday ) / 4 = 28
( Thursday + Friday + Saturday + Sunday ) = 112 ---------(3)
Let Thursday's temperature be X, then equation 3 becomes:
X + Friday + Saturday + Sunday = 112
Friday + Saturday + Sunday = 112 - X ---------(4)
Substituting equation (4) in equation (2), we get:
92 + 112 - X = 175
X = - 175 + 92 + 112
= 29°C.
Thursday's temperature = 29°C.