Answer:
see explanation
Step-by-step explanation:
The nth term of an AP is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given a₅ is double a₇ , then
a₁ + 4d = 2(a₁ + 6d) , that is
a₁ + 4d = 2a₁ + 12d ( subtract a₁ from both sides )
4d = a₁ + 12d ( subtract 12d from both sides )
- 8d = a₁
The sum of n terms of an AP is
= 
[ 2a₁ + (n - 1)d ] , substitute values
= 
( 2(- 8d) + 16d)
= 8.5(- 16d + 16d)
= 8.5 × 0
= 0
And the list below is where? So far 225 * 8 seems to be the only way to go
I disagree with Cassidy because:
Capacity is how much something can hold (etc. the capacity of this bowl is 5 grams)
Amount is how much of something (there are ten bottles of milk in the fridge. Ten is the amount of bottles of milk in the fridge)
Hope this helps,
What is the question you're trying to answer?
After 40 minutes, Ralph has already painted (40/60)/12=1/18 of the fence
Lisa's speed is 1/15 fence/hour, Ralph's speed is 1/12 fence/hour, hence when they help each other their combined speed is 1/15+1/12=3/20
Thus we need to solve 3/20*x=17/18 thus x=170/27 hours (approx 6 hours 15 mins)
