Answer: 32
Step-by-step explanation:
There are 18 boys and 14 girls (4 more boys than girls. 32 students total.
<h2>
Answer:</h2>
12
<h2>
Step-by-step explanation:</h2>
<u><em>The mean is also the average.</em></u>
Add up all the number of students all together:
12+13+14+9
48
Now, Divide the total amount of students (48) by the amount of numbers you added (in this case, 48/4 because we added 4 numbers wich are 12+13+14+9)
The average amount of students is 12
Unit digit=y
tens digit=x
the number: 10x+y
We suggest this system of equations:
x+y=7
(10y+x)=(10x+y)+9
we solve it by substitution method.
x=7-y
10y+(7-y)=(10(7-y)+y)+9
9y+7=70-10y+y+9
9y+10y-y=70+9-7
18y=72
y=72/18=4
x=7-y
x=7-4=3
number=10x+y=10*3+4=30+4=34
solution: the number: 34
To check:
3+4=7
43=34+9
