find the average of all the numbers between 6 and 34 which are divisible by 5. Choose the most appropriate option:  A) 18  B) 20  C) 24  D) 30  E) 32
<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">34 - 4</gadget>
<output>30</output>

<gadget id="calculator">10 + 30</gadget>
<output>40</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<result>B</result>
find the average of all the numbers between 6 and 34 which are divisible by 5.
divide(add(add(6, const_4), subtract(34, const_4)), const_2)
"solution average = ( 10 + 15 + 20 + 25 + 30 / 5 ) = 100 / 5 = 20 . answer b"