The price of a four star dinner was $100 two decades ago. a report says that a dinner is 250% of what it was 20 years ago, how much would it cost today?

For this case we can solve the problem by means of the following rule of three:

100 $ --------------> 100%

x -------------------> 250%

From here, we clear the value of x.

We have then:

Rewriting we have:

The price of a four star dinner today is $ 250.

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