Suppose an astronaut floating in space throws a rock. What will happen to the rock?

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

d is correct as long as you put the state each one it eg. (aq)

mg(no3)2(aq) + zn(s) > zn(2+)(aq) + ) + mg(s)

hope it !