I THINK,4=31
1=?
(1*31)/4=x
X=31/4
X=7.75minute to ride around the neighborhood once
It may not be correct
She should randomly select campers period, because she wants to estimate the percentage of "campers that ride once a week" and not for example what percentage of campers who ride that ride once a week...
Solution is supposed to be as follows
<span>u+<span>2 / 3</span><span> u<span>^3/2</span></span>
=r+<span>2 / 3</span><span> r^<span>3/2</span></span> + <span>c</span></span>
<h3>
Answer: 680 different combinations</h3>
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Explanation:
If order mattered, then we'd have 17*16*15 = 4080 different permutations. Notice how I started with 17 and counted down 1 at a a time until I had 3 slots to fill. We count down by 1 because each time we pick someone, we can't pick them again.
So we have 4080 different ways to pick 3 people if order mattered. But again order doesn't matter. All that counts is the group itself rather than the individual or how they rank. There are 3*2*1 = 6 ways to order any group of three people, which means there are 4080/6 = 680 different combinations possible.
An alternative is to use the nCr formula with n = 17 and r = 3. That formula is

where the exclamation marks indicate factorials