## rafeds08 Group Title express in roster form: B={xlxE N and 6<x<10} one year ago one year ago

1. myininaya Group Title

Just list all the natural numbers in the interval (6,10)

2. rafeds08 Group Title

B={7,8,9}

3. myininaya Group Title

Yep, that is right.

4. rafeds08 Group Title

thanks

5. myininaya Group Title

np

6. rafeds08 Group Title

what is np?

7. rafeds08 Group Title

myininaya', what if the set Q of all prime numbers less than 10? can we consider the negative numbers?

8. myininaya Group Title

I think it depends on the definition of prime numbers your teacher chose. I choose the definition that they are natural numbers greater than 1 and are only divisible by 1 and itself. For example: 13 since 13 and 1 are it's only factors

9. UnkleRhaukus Group Title

$\{n\in \mathcal N |(1<n<10)∧(\forall x,y\in \mathcal N)[(xy=n)⇒(x=1∨y=1)]\}$

10. myininaya Group Title

So do you think you can now list the prime numbers between 1 and 10 (not including 10 since it doesn't say equal to)?

11. rafeds08 Group Title

yap

12. rafeds08 Group Title

A math teacher is preparing an exam each of his Algebra class. Math-alino and Math-matalino, covering topics A (circles) and B (inequalities). He wants to design the exams so that both classes will have the same number of questions on A and also on B. Each question on A is worth 15 points in section Math-alino and 20 points in section Math-matalino while each question on B is worth 10 points in section Math-alino and 5 points in section Math-matalino. If the total number of points in both exams is 100, how many questions should he ask on each topic?

13. rafeds08 Group Title

help me please UnkleRhaukus thanks in advance

14. UnkleRhaukus Group Title

too confusing