We must find UNIQUE combinations because choosing a,b,c,d... is the same as d,c,b,a...etc. For this type of problem you use the "n choose k" formula...
n!/(k!(n-k)!), n=total number of choices available, k=number of choices made..
In this case:
20!/(10!(20-10)!)
20!/(10!*10!)
184756
It approximately the answer (17) if rounded
Answer:
The product is approximately 5400.
Step-by-step explanation:
9 1/16 rounded to the nearest whole number is 9.
645 3/5 rounded to the nearest hundred is 600.
Multiplying these values gives a product of 9·600 = 5400.
The product is approximately 5400.
Answer:
45 hours a week
Step-by-step explanation:
Ok, so we know that he worked 675 hours in 15 weeks.
So all we need to do is divide the hours by the amount of weeks, which is 15:
675/15= 45
So he worked 45 hours a week!
Answer: 
Step-by-step explanation:
Let be "x" the time in minutes a 150-pound person must walk at 4 mph to use at least 190 calories.
The amount of calories that a 150-pound person uses in 1 minute when walking at a speed of 4 mph is:
Therefore, knowing this, we can write the following proportion:
Finally, we must solve for "x" in order to find its value.
Multiplying both sides of the equation by 190, we get this result:
