Question

The average temperature for 3 days was 20 degrees. What must the temperature be on the fourth day to raise the average temperature for the four days to 20.5 degrees?

Answer 1

Answer:

22 degree

Step-by-step explanation:

Average temp for 3 days = 20

Let temp on day 1,2,3 be a,b,c degrees respectively.

Therefore, a+b+c = 20*3= 60 degrees

Now let temp on day 4 be d degrees.

Average temp for 4 days = 20.5 degrees

Therefore, a+b+c+d = 20.5*4= 82 degrees

Now we have,

a+b+c = 60, putting this in last equation

we get, 60+d= 82

Thus, d= 82-60= 22 degrees

So, the temperature on day 4 must be 22 degrees.

Answer 2

Answer:

22

Step-by-step explanation:

20.5 x 4 = 82                                                            

20 x 3 = 60

82 - 60 = 22

22