Question

A cell phone weighs about 2.8 times 10 Superscript n pounds. Which value of n is most reasonable? Negative 3 Negative 1 0 1

Answer 1

(B)-1

Explanation:

Let us plug in the given values into
`2.8X10^n`
`2.8X10^(-3)=2.8X 0.001=0.0028\:Pounds\\2.8X10^(-1)=2.8X 0.1=0.28\:Pounds\\2.8X10^(0)=2.8X 1=2.8\:Pounds\\2.8X10^(1)=2.8X 10=28\:Pounds`

A reasonable value for the weight of a cell phone will be 0.28 Pounds.

Therefore, n=-1

Answer 2

-1

Explanation:

The weight of the cell phone is given by:

`W=2.8*10^n`

The options provided for 'n' are:

a. -3

b. -1

c. 0

d. 1

Applying the possible values:

`W_a=2.8*10^(-3)\\W_a = 0.0028\ pounds\\\\W_b=2.8*10^(-1)\\W_b = 0.28\ pounds\\\\W_c=2.8*10^(0)\\W_c = 2.8\ pounds\\\\W_d=2.8*10^(1)\\W_d = 28\ pounds`

A cellphone could not possibly weigh as little as 0.0028 or as much as 2.8 or 28 pounds. Therefore, the most reasonable value for n is -1.