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:
40.8
Step-by-step explanation:
Answer:
2/3
Step-by-step explanation:
Do 1/3 divided by 4/5 first.
So we are going to flip 4/5 to 5/4. The equation is now:
1/4+1/3 times 5/4
Now we are going to do the multiplication since multiply and division is before adding and subtraction.
1/3 times 5/4 = 5/12
Now we have to add 1/4+5/12
With adding ( and subtracting) we have to find the common denominator which is 12
So now we have 3/12 + 5/12 = 8/12 which reduces to 2/3
Answer:
1 and 7/8 is the difference between the greatest and least amounts of rainfall.
Step-by-step explanation: