Answer:
5040
Step-by-step explanation:
The given series is :
24 + 48 + 72 + 96 +...+ 480
The first term, a= 24
Common difference, d = 24
The last term, 
Let there are n terms in the AP.
So,

There are 20 terms in the series. The sum of 20 terms is :

So, the sum of the given arithmetic series is equal to 5040.
Answer:10.5 ml
Step-by-step explanation:do 75/50=1.5
Do 7 times 2.6 and get 7+2.5=10.5 miles
Answer:
24 Years Old
Step-by-step explanation:
Less than 31 is 30 and 30-6=24
Let's first break it down to the time 8 people need for one wall. That would be 10 minutes, right? If one person would have to do it in stead of 8, you'd expect him to take 80 minutes.
To paint 7 walls, he would nee 7x80 = 560 minutes. 10 people would do that 10 times faster, ie., 56 minutes.
I know puzzles like these always have a mindtrick. Did I miss anything?? ;-)
Answer:
Her answer is wrong because she the object cannot hit the ground at negative seconds. She could’ve have used other methods because she used the quadratic formula. The advantages is that it works for every situation. The disadvantages is that it takes longer. She should’ve used a different method.
Step-by-step explanation: