Please I need some help on this question I don't know how to create a calculation for the distance and when to break it .

Question

The snail climbs up 7 feet each day and slips back 2 feet each night.
How many days will it take the snail to get out of a well with the given depth?

Sample Input:
31

Sample Output:
6

Explanation: Let's break down the distance the snail covers each day:
Day 1: 7-2=5
Day 2: 5+7-2=10
Day 3: 10+7-2=15
Day 4: 15+7-2=20
Day 5: 20+7-2=25
Day 6: 25+7=32
So, on Day 6 the snail will reach 32 feet and get out of the well at day, without slipping back that night.

Answer 1

a = first term
d = common difference
n = term
an = distance covered by snail on a particular
day.

formula: a + (n - 1)d = an

Answer 2

Obinna Anosike First observe that every time we reach a new distance, we reach it with the 7-step, so there are always one more 7-step than 2-steps. After n days we reach distance d:

7*n - 2*(n-1) = d <=>
7*n - 2*n + 2 = d <=>
5*n = d - 2 =>
n = ceil((d-2)/5)

Lets plug 32 in:
n = ceil((32-2)/5) = ceil(30/5) = 6 days

Answer 3

I don't understand please explain

Answer 4

Is n the unknown to find which is the days