(1)
we are given
we can find for y
multiply both sides by 6
we can see that y is directly proportional to x
so, option-D........Answer
(2)
y varies inversely with x
so, we can write it as
now, we are given
y=5 when x=2.5
so, we can plug it here
and then we can solve for k
now, we can plug back
we can plug x=20
.............Answer
(3)
we are given
The current, I, in a circuit varies inversely with the resistance, R
so, we can write it as
we have R=12 when I=3
so, we can plug it
now, we can solve for k
now, we can plug back
we can plug R=6
................Answer