Answer: 
Step-by-step explanation:
1. By definition, scientific notation has the following form:
Where:
<em> a</em> is a number between 1 and 10 but does not include 10.
<em> b </em>an integer.
2. When you multiply 3.25 by 7.8 the result is 25.35 and when you multiply 
by 
, you obtain 
, but to write ree thsult in scientific notation, the decimal point must be after the first digit. Therefore, you must move the decimal point one place to the left. So, the exponent changes from 9 to 10:
We can determine the value of the adult ticket cost and student ticket cost by following these steps:
1. solve form one of the variables from one of the equations
Let's solve for a from 2a + 2s = 40
2a + 2s = 40
2a + 2s - 2s = 40 - 2s
2a = 40 - 2s
2a/2 = 40/2 - 2s/2
a = 20 - s
2. Replace the expression found and solve for s
4a + 5s = 87
4(20 - s) + 5s = 87
4×20 - 4×s + 5s = 87
80 - 4s + 5s = 87
80 + s = 87
80 - 80 + s = 87 - 80
s = 7
3. Replace 7 for s into a = 20 - s
a = 20 - 7
a = 13
Then, a = 13 and s = 7.
Then the adult ticket cost is $13 and the student ticket cost is $7
Given:
Triangle EFG and EHG are two right triangles.
To find:
The values of x and y.
Solution:
In triangle EFG,
[Angle sum property]
In triangle EHG,
[Angle sum property]
Therefore, the value of x is 25 and the value of y is also 25.
Answer:
Step-by-step explanation:
First let us consider how we calculate the mean test mark in the first place, we add up the individual test marks of the entire class to give the total test mark then we divide by the number of students. This means we need two pieces of information to calculate the boys' mean mark, the total boys' mark and the number of boys. We already know the number of boys but how do we work out the total boys' test mark? If we can work out the total class mark and total girls' mark we can find the total boys' mark by subtracting the total girls' mark from the total class mark. To do this we can work backwards to find the total mark for the whole class by taking the mean mark and multiplying it by the number of students, this gives us Total Class Mark = Mean Class Mark x Number of Students = 60 x 30 = 1800. We can do the same for the girls' mark giving us Total Girls' Mark = Mean Girls' Mark x Number of Girls = 54 x 20 = 1080. This then gives us the total boys mark as Total Boys' Mark = Total Class Mark - Total Girls' Mark = 1800 - 1080 = 720. Now we have everything we need to work out the boys' mean mark and we get Boys' Mean Mark = Total Boys' Mark/Number of Boys = 720/10 = 72.
