There were 40 desks in a class. The teacher wanted to arrange the desks in a rectangle with at least 4 desks in each row and column. Which of the following is a possible desk arrangement? A) 20 rows and 20 columns
B) 5 rows and 8 columns
C) 2 rows and 20 columns
D) 7 rows and 7 columns

B) 5 Rows and 8 Columns

Step-by-step explanation:

First you take the information from the question to know that C is wrong. This is because It has only 2 desks in rows and the question asks for 4 desks in rows and columns. Next you know that you have 40 desks so the two numbers need to multiply to 40. This makes A and D wrong, leaving your answer as B.

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.