<p>1.
The digits 1,2,3, and 4 are to be arranged randomly to make a positive four-digit integer. What is the probability that the digits 1,2,and 3 will be directly next to each other, in that order, from left to right ?</p>
<p>2.At North High School, the ski club has 15 members and the debate club has 12 members, If a total of 11 students belong to only one of the two clubs, how many students belong to both clubs?
(A) 2
(B) 7
(C) 8
(D) 12
(E) 16</p>
<p>Could anyone explain to me detailly pleaseeeeee ?</p>
<p>There are 27 total students in the 2 clubs combined. These include students in only 1 club and students in both clubs. You subtract out the kids in only 1 club to get the kids in both.</p>
<p>27-11 = 16 in both.</p>
<p>Also, sometimes they give the # of kids in both and ask for the # of kids in only one. The process is the exact same.</p>
<p>The digits 1,2,3, and 4 are to be arranged randomly to make a positive four-digit integer. What is the probability that the digits 1,2,and 3 will be directly next to each other, in that order, from left to right ?</p>
<p>There are only 2 suitable numbers: 1234 and 4123
There are 4! possible permutations of 4 digits</p>
<p>Actually, I don’t think that the answer is 16. I think it’s 8.
There are 16 students in both. However, there are two groups, so the number of students is 8. Correct me if I’m wrong.</p>
<ol>
<li>2/4!
2.there are 27 ‘memberships’ total. only 11 people in 1 club therefore there are 16 ‘memberships’. The people that have these ‘memberships’ all are in 2 clubs. Therefore there are 8 people that are in both clubs as 16/2=8.</li>
</ol>