Answer:
1/4.
Step-by-step explanation:
That is 1 - (1/4 + 2/5 + 1/10).
The Lowest common multiple 4 5 and 10 is 20 so we have
20/20 - (5/20 + 8/20 + 2/20)
= 20/20 - 15/20
= 5/20
= 1/4 answer.
Let the difference between consecutive terms be D. If the middle term is 30, then the term before it is 30-D, and the term after it is 30+D. So the sum of these three terms would be (30-D) + 30 + (30+D) = 3*30.
Extending this sum to include all 11 terms centered around 30, we see that any addition of D is canceled by a balanced subtraction, leaving you with 11 copies of 30. So the value of the sum is 11*30 = 330.
If you do 81 x 9 which equals 729. If you want to check, you do 729 divided by 9 and you get 81.
