Question

if x varies inversely as y and x is equal to 10 then Y is equal to 8
then find Y when x is equal to 4

Answer 1

X inversely to y
y=k×1/x
xy=k.........(1)
x=10 & y=8
substitute in eqn (1)
10×8=k
80=k
when x=9 put eqn value of k and x
8×y=80
y=80/8
y=10

Answer 2

Answer:

x1= 10 y1=8

x2= 4 y2=?

x1:x2::y2:y1

10:4::y:8

10/4=y:8

4y= 80

y=80/4

y=20