Step-by-step explanation: Given that Kristie has taken five tests in science class. The average of all five of Kristie's test scores is 94 and the average of her last three test scores is 92.

We are to find the average score of her first two tests.

Let a1, a2, a3, a4 and a5 be teh scores of Kristle in first , second, third, fourth and fifth tests respectively.

Then, according to the given information, we have

$\dfrac{a1+a2+a3+a4+a5}{5}=94\\\\\Rightarrow a1+a2+a3+a4+a5=94\times5\\\\\Rightarrow a1+a2+a3+a4+a5=470~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)$

and

$\dfrac{a3+a4+a5}{3}=92\\\\\Rightarrow a3+a4+a5=92\times3\\\\\Rightarrow a3+a4+a5=276~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(ii)$

Subtracting equation (ii) from equation (i), we get

$(a1+a2+a3+a4+a5)-(a3+a4+a5)=470-276\\\\\Rightarrow a1+a2=194\\\\\Rightarrow \dfrac{a1+a2}{2}=\dfrac{194}{2}\\\\\Rightarrow \dfrac{a1+a2}{2}=97.$

Thus, the average of the first two test scores is 97.

6 0

3 years ago

Kit charges customers an initial fee plus a certain amount per hour to walk their pets. The table below shows the amount of mone

Luda [366]

Answer:

The answer would be 7.5

Step-by-step explanation:

This is due to if there were to be a chart it would start at 15 then continue by 7.5 which would then lead to 1 hour which is 22.5 min additionally other people are not answering this because you did not give all the information such as the chart etc and the answers unlike me i have the toolds and the questions.

8 0

3 years ago

Which statements are true? Mark all that apply.

FrozenT [24]

Answer:

A and D

Step-by-step explanation:

3 0

2 years ago

Find the area of a regular pentagon with a side of 10cm and an apothem of 6.9cm￼

Find the area of a regular pentagon with a side of 10cm and an apothem of 6.9cm