Answer:

Step-by-step explanation:
-The total volume will be the sum of the volumes of the triangular section plus the rectangular section.
#Volume triangular section:

#Volume rectangular section:

#Total volume of the doorstep:

Hence, the doorstep's volume is 
Answer:
There is no real number root
Step-by-step explanation:
There is no real number root because there is a negative number inside the root.
Answer:
How many friends?
Step-by-step explanation:
we know that
Any function f(x) is continuous at x=a only if

We can see that this curve is smooth everywhere except at x=3
so, we will check continuity at x=3
Left limit is:

Right limit is:

Functional value:

we can see that left limit is not equal to right limit
so, limit does not not exist
so, this function is discontinuous at x=3
Since, limit does not exist
so, there will be non-removal discontinuity at x=3
so, option-C........Answer