Answer:
sorry foe being late
Step-by-step explanation:
Answer:
Arithmetic sequence states that a sequence of numbers such that the difference between the consecutive terms is constant.
it is given by:
where a is the first term , n is the number of term and d is the common difference.
Given the series: 
here, Common difference(d) = 5
First term(a) = 49
by definition we have;
For nth term

= 5n + 44
To write the series using summation notation for 14 terms
Summation symbol 
The series for 14th terms is given by;

Quadrant I or QI
This is tough to explain but here I go
If x and y is positive, it's QI
If x is negative and y is positive it's QII
If x and y are negative, it's QIII
If x is positive and y is negative It's QIV
So the answer is C
Hopes this helps :D
21 blocks, because if he uses 38 you subtract 17 and you get 21