The mean temperature for the first 4 days in January was 1°C. The mean temperature for the first 5 days in January was 3°C.
What was the temperature on the 5th day?

Step-by-step explanation:

mean is average, so if we label the first through fifth days of january a-e we can solve it.

So average of the first four is (a+b+c+d)/4 = 1 and the first five is (a+b+c+d+e)/5 = 2.  Since it's easy, let's get rid of the fraction in both.

(a+b+c+d)/4 = 1 and (a+b+c+d+e)/5 = 2

a+b+c+d = 4 and a+b+c+d+e = 10

Now, we know a+b+c+d is 4, so we can replace that in the second equation

a+b+c+d+e = 10

4 + e = 10

e = 6

ad since e is the fifth day, we know the temperature of it.  Let me know if something here didn't make sense

you never say the total so we cant find the percentage used for petrol

step-by-step explanation:

step-by-step explanation:

given perimeter: 28cm

length: 9cm

atp,

2(l+w)=p of the reactangle

2(9+x)=28

18+2x=28

2x=28-18

x=10/2

x=5

therefore width is 5 cm