To start, this is an interest problem, meaning you will have to use I=prt where I is the total interest, p is the principle amount, r is the rate, and time is the amount of time in years. Since you know the principle rate is $1200, the rate is 3.9%, and the time is 8 months, you can plug this into the formula. However, keep in mind that you have to convert 3.9% to a decimal before putting it into the formula and the time must be represented in years. 3.9% represented as a decimal would be 0.039 and 8 months would be represented as 8/12 or 2/3 (since there are 12 months in one year). Now that you have this information, plug the values into the formula: i=(1200)(0.039)(2/3). When simplified, you get your answer as $31.20.
Answer:
Adult= $11
Children = $7.5
Step-by-step explanation:
Let x represent adult ticket and y represent children ticket
2x + 3y= 44.50........equation 1
3x + 6y= 78........equation 2
From equation 1
2x + 3y= 44.50
2x= 44.50-3y
x= 44.50-3y/2
Substitute 44.50-3y/2 for x in equation 2
3x+ 6y= 78
3(44.50-3y/2) + 6y= 78
66.75- 4.5y +6y= 78
66.75 + 1.5y= 78
1.5y= 78-66.75
1.5y= 11.25
y= 11.25/1.5
y = 7.5
Substitute 7.5 for y in equation 1
2x + 3y = 44.50
2x + 3(7.5)= 44.50
2x + 22.5= 44.50
2x = 44.50-22.5
2x= 22
x= 22/2
x= 11
Hence the price of adult ticket is $11 and the price of children ticket is $7.5
I think you mean in terms of 
?
Recall Euler's identity
and de Moivre's theorem
where 
.
It follows that
By the binomial theorem, expanding the right side gives
and so
We can factorize this as
and using the Pythagorean identity
this reduces to
