Kayley has a craft box full of buttons. The craft box has 6 yellow buttons, 7 black buttons, 4 red buttons, 2 pink buttons, 8 green buttons, and 3 brown buttons. If Kayley is randomly choosing buttons out of the box one at a time and then returning them, choose all the statement that is true. 

Answer is in the photo. I can't attach it here, but I've uploaded it to a file hosting. link below! Good Luck!

cutt.ly/Kzv78uJ

D. Kayley has a 4/5 chance in picking a button that is not yellow.

Step-by-step explanation:

54

step-by-step explanation:

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for