Question

If y is directly proportional to 1 by x and x equal to 21 y equal to 20 what is the value of x when y equal to 1.25

Answer 1

y is directly proportional to 1/x
y=k/x. where k is constant
k=xy..........….........1
k=21×20=420
if y=1.25
from 1
420=x×1.25
x=420/1.25=336