Answer:
56.25 pound of the coffee that costs $5 per pound is needed
18.75 pound of the coffee that costs $9 per pound is needed
Step-by-step explanation:
Let the number of pounds be x and y respectively
The total pounds is 75;
So;
x + y. = 75 •••••••(i)
Total cost of first type
9 * x = $9x
Total cost of second type;
5 * y= $5y
75 pound at $6 per pound; total cost of this is;
6 * 75 = $450
Thus;
9x + 5y = 450 ••••••••(ii)
From i, x = 75-y
Put this into ii
9(75-y) + 5y = 450
675 -9y + 5y = 450
4y = 675-450
4y = 225
y = 225/4
y = 56.25
x = 75 - y from i
x = 75-56.25
x = $18.75
Answer:
Step-by-step explanation:
If the population increases at a rate of 4% per annum, then:
In year 1:
Where 
is the initial population and 
is the population in year n
In year 2
It can also be written as:
Taking out common factor
Taking out common factor (1 + 0.04)
Taking out again common factor
Simplifying
So
This is the equation that represents the population for year n
Then, in 4 years, the population will be:
