Answer:
You would usually use 3.14
Step-by-step explanation:
It kind of depends on where you are using it. In an equation, pi would be used as 3.14 and the answer would be approximated. To write it anywhere else (I dont know where else you would though), you would do the pi symbol. I hope this helps.
The answer is 10% because 10% of 40 is 4
It is multiplying by 20. Therefor output for 10 would be 200. the missing input would be 8 making the output 160
Answer:
8 centimeters.
Step-by-step explanation:

Divide 3 both sides:

Multiply 4 on both sides:

8cm on the map represents 20km.
we need to find the unit form in 2 tens and one multiplied with 10 .' we know that
21 is the 2 tens one
if we multiplied 21 with 10 we get 210 .
which means 21 tens are there in 210.which is the unit form of 210.