Answer:
X+13=116
Step-by-step explanation:
Nineteen and two hundred and thirty eight thousandths
a. The first part asks for how many ways they can be seated together in a row. Therefore we want the permutations of the set of 6 people, or 6 factorial,
6! = 6
5
= 30
4
= 360
2 = 720 possible ways to order 6 people in a row
b. There are two cases to consider here. If the doctor were to sit in the left - most seat, or the right - most seat. In either case there would be 5 people remaining, and hence 5! possible ways to arrange themselves.
5! = 5
4
= 20
3
= 120
1 = 120 possible ways to arrange themselves if the doctor were to sit in either the left - most or right - most seat.
In either case there are 120 ways, so 120 + 120 = Total of 240 arrangements among the 6 people if the doctor sits in the aisle seat ( leftmost or rightmost seat )
c. With each husband on the left, there are 3 people left, all women, that we have to consider here.
3! = 3
2 6 ways to arrange 3 couples in a row, the husband always to the left
<h3><u>The first number, x, is equal to 7.</u></h3><h3><u>The second number, y, is equal to 2.</u></h3>
x + 2y = 11
2x + y = 16
We can subtract 2y from both sides of the first equation to get a value for x.
x = 11 - 2y
Because we have a value for x, we can plug it into the second equation.
2(11 - 2y) + y = 16
Distributive property.
22 - 4y + y = 16
Combine like terms.
22 - 3y = 16
Subtract 22 from both sides.
-3y = -6
Divide both sides by -3.
y = 2
Now that we have a value for y, we can plug it into either equation to solve for x.
x + 2(2) = 11
x + 4 = 11
Subtract 4 from both sides.
x = 7