Answer:
Hanna donated b/50 books
Step-by-step explanation:
In this problem, we have:
n = 150 number of students at Hanna's school
b = ? number of total books donated by the students
Also, Hannah has donated 3 times as many as the average number of books each student donated.
The average number of books each student donated can be written as:
And calling
h = number of books donated by Hannah
This means that
Simplifying, this can be rewritten as
£7200
In first year depreciates by 20%, that is it is worth 80% of it's original value
80% = = 0.8
value after 1 year = 0.8 × £10000 = £8000
In the second year it depreciates by 10% of it's value, that is it is worth 90% of it's value at the end of the first year.
90% = = 0.9
value after 2 years = 0.9 × £8000 = £7200