The answer would be 100/101 if we follow according to the rule on which the sequence is based on!
The lines are intersected at point (0, -5). So (0, -5) is the solution.
Answer is the third one
(0,-5 )
The first discounted price is given through the equation,
discounted price = ($3.45)(1 - 0.20) = $2.76
Then, due to the privilege of being a Coles-Myer discount card holder, another 7.5% discount is given. Such that the final price would be,
final price = ($2.76)(1 - 0.075) = $2.553
The total amount saved up is equal to,
$3.45 - $2.553 = $0.897
I've attached a plot of one such cross-section (orange) over the region in the x-y plane (blue), including the bounding curves (red). (I've set

for this example.)
The length of each cross section (the side lying in the base) has length determined by the horizontal distance

between the y-axis

and the curve

. In terms of

, this distance is

. The height of each cross section is twice the value of

, so the area of each rectangular cross section should be

.
This means the volume would be given by the integral
512=2w^2 is the best answer