Abox of pencils costs $10.the total cost (c) as a function of the number of boxes (b) is expressed as c = f(b) = 10b. what is the domain of this function?
a.
all positive integers and zero
b.
all real numbers
c.
all real numbers except 0
d.
all positive real numbers except 10

All positive integers and zero

A is correct

Step-by-step explanation:

A box of pencils costs $10

The total cost (c) as a function of the number of boxes (b) is expressed as

c = f(b) = 10b

The function, f(b) = 10b

b is independent variable and c is dependent variable.

For any function find domain using independent variable.

b represents number of boxes.

Number of boxes neither be negative nor decimal.

Possible value of b: {0,1,2,3,4,5,}

All positive integers and zero.

Domain: All positive integers and zero

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.

16.80 times .20= 3.36

step-by-step explanation: