Derek has already spent 23 minutes on the phone, and he expects to spend 1 more minute
with every phone call he routes. In all, how many phone calls does Derek have to route to
spend a total of 47 minutes on the phone?

hi

Step-by-step explanation:

hi

, 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

b

step-by-step explanation: