If a ramp were coated with a smoother surface, the ramp’s efficiency would increase because friction would decrease decrease because friction would increase increase because friction would increase decrease because friction would decrease

Increase because friction would decrease.

Coating the ramp with a smoother surface will decrease the friction. A decrease in friction will help to slide any object up the ramp easily. Thus, a lesser energy will be spent as compare to earlier. Hence, the ramp's efficiency will increase.

r = ρ x length / area  

ρ = r x area / length  

ρ is in ohm-meters  

in basic units, it is m³kg/s³a²  

i think this is it.

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form