Answer:
(a) 120 choices
(b) 110 choices
Step-by-step explanation:
The number of ways in which we can select k element from a group n elements is given by:

So, the number of ways in which a student can select the 7 questions from the 10 questions is calculated as:

Then each student have 120 possible choices.
On the other hand, if a student must answer at least 3 of the first 5 questions, we have the following cases:
1. A student select 3 questions from the first 5 questions and 4 questions from the last 5 questions. It means that the number of choices is given by:

2. A student select 4 questions from the first 5 questions and 3 questions from the last 5 questions. It means that the number of choices is given by:

3. A student select 5 questions from the first 5 questions and 2 questions from the last 5 questions. It means that the number of choices is given by:

So, if a student must answer at least 3 of the first 5 questions, he/she have 110 choices. It is calculated as:
50 + 50 + 10 = 110
Answer: 7500
Step-by-step explanation:
multiply 150 by 50
Answer:
6
Step-by-step explanation:
pls brainliest
9/2=4.5
27/4.5=6
Answer: No idea, sorry. I'm sure you could look it up tho
Step-by-step explanation:
Answer:
28 numbers
Step-by-step explanation:
There is a distance of 81 between -0.5 and 80.5. Divide this number by 3, since you are only counting every third number and you will get 27, but you need to count the first number, which has been excluded. Add one more to get the answer, 28.