Answer:
4 tens
Step-by-step explanation:
3 tens would get you $30, which is $7.80 short. If you give 4 tens you are giving $40 which is 2.20 more than $37.80, which is okay as you can probably get change and it is the least amount of tens you can give to cover the cost.
Answer:
÷ 
Step-by-step explanation:
Evaluate
÷
, then evaluate each given expression to find which of them will give us the same result.
÷ 
÷
(recall: 
÷ 
(changing from division operation to multiplication by flipping the fraction to our right upside down)

Let's compare the expressions in the given options to the value we got above:
Option 1: 3*3⁶
= 3*729 = 2,187 (this is equal)
Option 2: 3⁷ ÷ 3⁰
= 2,187 ÷ 1 (recall: x⁰ = 1, therefore, 3⁰ = 1)
= 2,187 (this is equal)
Option 3: 3³ * 3⁴
= 27*81 = 2,187 (this is equal)
Option 4:
÷ 
÷ 
÷ 
(changing from division to multiplication)
(not equal)
÷
i not equal to
÷
.
Answer:
$5,500
Step-by-step explanation:
Let A be the amount invested at 3%, B the amount at 4%.
Total value:
1.A%2BB=8000
Interest:
Multiply eq. 1 by -3 and add to eq. 2,
-3A-3B%2B3A%2B4B=-24000%2B29500
highlight%28B=5500%29
Then from eq. 1,
A%2B5500=8000
highlight%28A=2500%29