Question

X,yand z are three quantities.X varies inversely with y when z is constant.Y varies inversely with z when x is constant.When y=8,and z=7,x=30.Find x if y=16 and z=21.

Answer 1

hey buddy here is your answer

==> X Y= A, Z = B --- condition 1

==> Y Z = C ,X = D -- condition 2

now X/Z = A/C also Z/X = B/D

so,

A/C = B/D (cross multiply)

A*D = B*C

so by this we can

==> 8*7*30 = x*16*21

==> 1680 = x*336

==>1680/336 = x

==>5 = X

Hope it helps

Answer 2

we have three quantities mentioned X, Y and Z along with two conditions.

The constant K placed in the above equation is to simplify the proportionality equation and will be striked off as it eventually gets divided since we have the constant on both the conditions.

Hope this helped :)