On day one she starts of with 1 hour so it will be 1+30x. X being the number of days so by the seventh day Anna would practice for 240 minutes.
It is given in the question that
You work at a T-shirt printing business. Of 1,300 T-shirts shipped, 106 are imperfect.
So out of 1300 T-shirts, number of perfect t-shirts are

So probability that the t-shirt is printed correctly is

And to find the percentage, we have to multiply it by 100, and on doing so we will get 92 % .
(14 over 5) · (15 over 5)
= 14·13·12·11·10/5! · 15·14·13·12·11/5!
= 6012006
(n over k) is the Binomial coefficient
B+ 11/3= -2
⇒ b= -2 -11/3
⇒ b= -6/3 -11/3
⇒ b= -17/3
⇒ b= -5 2/3
Final answer: b= -5 2/3~