Assuming the order does not matter, you want the number of combinations of 9 things taken 5 at a time. The combinations can be shown as C(9,5), 9C5.
C(9, 5) =
9/5(9-5) =
9*8*7*6*5 / 5*4
The 5 terms cancel.
9*8*7*6 / 4*3*2 =
9*7*2 =
126
The above change is because 4*2 cancels the 8 in the numerator and 6/3 = 2
Therefore, the solution is 126.
Sue's total pay of year will have three parts
1) Fixed Salary for 12 months
one month salary = £1410
so 12 month salary = £1410 x 12 = £16920
2) 26% of total profit
Total cost to the company- £473,500
Total income for the company - £549,000
Profit = Total income for the company - Total cost to the company
= £549,000 - £473,500 = £75500
Sues income from profit = 26% of £75500 = (26 × 75500)/100 = £19630
3) Bonus if Sue sells at least 16 cars
Given number of months when sue solds atleast 16 cars = 4
So bonus income = 4 × 390 = £1560
Adding the three above parts
Sue's total pay for the year = £16920 + £19630 + £1560 = £38110
Use a porportion to help better and speed up the process
Have two sets of parallel sides
