Well. add all of these up 8+5+5. we know 5+5 is 10. and 10+8 is 18. so 18 is the denominator. There are 8 red markers and 5 blue markers at 8 and 5 up. 8+5 is 13 right? So the numerator will be 13. but the probability of picking a blue then a red is 13 alone or if you are ask for out of the amount of markers there are, its 13/18. so the probability is 13 or 13/18.
He had 40 pencils left after he gave away 8, so originally he had 40 + 8 pencils, which is 48.
Now, he bought 4 packages, which had a total of 48 pencils, so divide 48 by 4, which is 12. He had 12 pencils in each package.
To determine the solution arithmetically, first add 8 to 40, then divide 48 by 4.
To determine the solution algebraically, set up and solve the equation 40 = 4x - 8.
Each package contained 12 pencils.
Hope this helps
4:6
6:9
12:18
And it goes on