<h2><em><u>Solution</u></em> : </h2>
let the last number be x
we know,

So,





therefore, the last number is 10.
9514 1404 393
Explanation:
"Like" radicals can be added and subtracted in the same way any like terms can be combined. It can be helpful to simplify the radical as much as possible so that it can be seen whether the radicals are "like" or not.
<u>Examples</u>:
√2 +√3 . . . . cannot be combined
√2 +√8 = √2 +2√2 = 3√2 . . . . the simplified radicals can be combined
Answer:
C
Step-by-step explanation:
There is a common ratio between consecutive term in the sequence, that is
÷
= 3 ÷
= 30 ÷ 3 = 300 ÷ 30 = 10
This indicates the sequence is geometric with n th term
= a
where a is the first term and r the common ratio
Here a =
and r = 10 , thus
=

=
× 
= 3 ×
× 
= 3 × 
Thus
= 3
→ C
There are 3260 quarts in 815 US gallons