The average temperature of a certain city on different days is as follows:
Monday, Tuesday, Wednesday and Thursday = 42º
Tuesday, Wednesday, Thursday and Friday = 44º
What is the temperature on Friday if the ratio of the temperature on Monday and Friday is 3 : 5?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 20º.
We know that,
Average = Sum of observations/Number of observations
So,
Sum of temperature on Monday, tuesday, wednesday and thursday = 42 × 4 = 168 ---- (2)
Sum of temperature on tuesday, wednesday, thursday and friday = 44 × 4 = 176 ----- (3)
Applying (3) - (2), we get
⇒ Friday - Monday = 8
Ratio between Monday and friday = 3 : 5 = 3x and 5x
According to the question;
⇒ 5x - 3x = 8
⇒ 2x = 8
⇒ x = 4
Hence, the temperature on friday = 5x = 20°