Answer:

Step-by-step explanation:
In order to write the series using the summation notation, first we need to find the nth term of the sequence formed. The sequence generated by the series is an arithmetic sequence as shown;
4, 8, 12, 16, 20...80
The nth term of an arithmetic sequence is expressed as Tn = a +(n-1)d
a is the first term = 4
d is the common difference = 21-8 = 8-4 = 4
n is the number of terms
On substituting, Tn = 4+(n-1)4
Tn = 4+4n-4
Tn = 4n
The nth term of the series is 4n.
Since the last term is 80, L = 4n
80 = 4n
n = 80/4
n = 20
This shows that the total number of terms in the sequence is 20
According to the series given 4 + 8 + 12 + 16 + 20+ . . . + 80
, we are to take the sum of the first 20terms of the sequence. Using summation notation;
4 + 8 + 12 + 16 + 20+ . . . + 80 = 
The propeller-driven airplane has over the jet is that maximum thrust is ... efficiency at the higher altitudes is lost (turbofan engines are ... pilot is worse off than the propeller pilot. For ... applicable speed limit at all times.
Answer:
6
Step-by-step explanation: because its online
Answer:
$1920
Step-by-step explanation:
Original amount: £1200 x Simple interest rate: 0.2 x number of years: 3 = 720
Add Original onto simple interest
£1200 + £720 = £1920
Total Cost of personal loan after 3 years = £1920