Which one is the correct answer

b. 4 cm

Step-by-step explanation:

Area(A) = 60cm^2

First calculating the radius(r)

we know

Area =

60 =

Here pie will be cancelled

60 =

r = cm

r =

Now

Calculating Circumference

= 2r

= 2 * * 2

= 4 cm

Hope this was  helpful.:)

step-by-step explanation:

one of the most important purposes of surface treatment is to alter surface properties according to the requirement of specific applications. for example, hydrophobic coating has been utilized on windshield and eyeglasses. gold atom monolayer on substrate has become a popular surface bioconjugation strategy.  

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.