Caleb has 20 more books than Danica. If Caleb gives Danica half of his books, Danica will have 4 more books than Caleb. How many books did Caleb have to start with? E. 24 F. 34 G. 44 H. 55

Option E: 24.

Step-by-step explanation:

When Caleb (C) has 20 more books than Danica (D), we have:

  (1)

Now, when Caleb gives Danica half of his books:

  (2)

Danica will have 4 more books than Caleb, so:

    (3)    

Also we have that:

  (4)  

By entering equation (2) and equation (3) into equation (4) we have:

  (5)

From (1) we have:

  (6)

By entering (6) into (5):

And, from (6):

Therefore, the correct option is E, Caleb had to start with 24 books.

I hope it helps you!          

738 square ft

Step-by-step explanation:

Area of the composite figure

= 21*(12 + 9 + 6) + 9*(9 + 6) + 6*6

= 21*27 + 9*15 + 6*6

= 567 + 135 + 36

= 738 square ft