Two quantities vary inversely. If the value of the first is 15 when the value of the second is 18, find the value of the second quantity when the first is 10.
If X and Y are the two quantities, the relevant equation is: Y = k/X.
To find the value of k for this problem, enter the given values of X and Y ---> 18 = k/15
multiply both sides by 15: k = 270
So, the final equation for this situation is: Y = 270/X
When X = 10 ---> Y = 270/10 ---> Y = 27