Find the function?

Question

The function gives the cost of a certin item is defined as

C(x)=

5x if o 4x if 10< or equal to X<30
3.5x if 30< or equal to X<60
3.25x if X> or equal to 60

Where X is the number of pounds of a certin commodity sold and c(x) is measured in dollars. Determin the value of X foe wchich the function C is discontinous?

Answer 1

for x = 10 c(x) is not defined and can not be defined continuous.

X = 9.99999 C(x) is a bit less than 50
X = 10.0000001 C(x) is a bit more than 40

I assume that

10< or equal to X<30 means 10

Answer 2

the values of x at which c is discontinuous are
X=10, x=30, x=60 because limit of c(x) as x approaches these values from the left isn't equal to c(x). the limits at these points actually don't even exist since c(x) doesn't approach the same limit from both sides.

Answer 3

at x=10, ,the function is not defined. so c(x) must be discontinuous there.

but i believe that its a typo, so i assume c(x)=5x for 0
at x=10 c(x)=5*10 = 50

but alsp c(x) = 4x = 40

therefore x is discontinuous at 10


similarly it is disco.. at 30,60