Question

If z varies directly as x and inversely as y. Find the percentage increase in z due to an
increase of 12% in x and a decrease of 20% iny.​

Answer 1

Z is proportional to x & y as ;

Z is proportional = x / y
Assuming the constant of proportionality to be 1 ; we can say that-
Z = x/y

Change in x = 100x+12x
Change in y = 100y - 20 y

Z = 112x / 80 y

% increase in Z = change in z / initial value of z * 100

= ((112x/80y - x/y ) / (x/y))*100 = 32x/80y / (x/y) * 100
= 40%