Answer: 
Step-by-step explanation:
Given
It takes 20 min and 30 min for a person and his friend to paint a wall individually i.e.
In 1 min they cover
part and
part of wall respectively.
If the work together, 1 minute work is

Time required will be reciprocal of it

Answer:
Yes
Explaination:
They are similar and the ratio is still the same. The artwork's shape didn't change we just resized it by multiplyting its length and width by 2.
V = 297 for a square pyramid, I hope its right..
The first one is 5
Second 3
Third -7
Fourth is 9
And fifth is 10