Answer:
The answer is D) 60
Step-by-step explanation:
Given:
The sequence is 25, 20, 15, 10, 5.
To find:
The ninth term of the given sequence.
Solution:
We have,
25, 20, 15, 10, 5
It is an AP because the difference between two consecutive terms are same.
Here,
First term (a) = 25
Common difference (d) = 20-25
= -5
The nth terms of an AP is
Where, a is the first term and d is the common difference.
Putting a=25, n=9 and d=-5 to get the 9th term.
Therefore, the ninth term of the given sequence is -15.
(2x+1)+89=180. 180 is the angle of a straight line. Set your two known sides equal to 180 and solve for x if needed.
"If and only if" (abbreviated "iff") is a biconditional logical connective between two assertions that is either true or untrue. The correct option is D.
<h3>What is "if and only if" operator?</h3>
In logic and related subjects such as mathematics and philosophy, "if and only if" (abbreviated "iff") is a biconditional logical connective between two assertions that is either true or untrue. It is represented by ⇔ or ↔.
The two of the events are
- p: the whole number has one digit.
- q: the whole number is less than 10.
Now, the representation of "the whole number has one digit if and only if the whole number is less than 10" is done as p ↔ q.
Hence, the correct option is D.
Learn more about "if and only if" operator:
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