How will placing tip tanks on the wings affect drag potential (DP) or induced drag (Di)?

Placing tip tanks on the wings primarily serves to enhance the aircraft's performance and modify its aerodynamic characteristics. When tip tanks are added, they can help to improve the lift distribution along the wing span, which directly affects induced drag.

Induced drag arises from the generation of lift; as lift increases, induced drag also tends to increase. However, by redistributing the lift more evenly across the wing due to the addition of the tip tanks, the overall induced drag can decrease. This is because tip tanks increase the effective span of the wings, which reduces the strength of the vortices that form at the wingtips. These vortices are a significant contributor to induced drag.

On the other hand, the addition of tip tanks usually results in increased drag potential (DP) due to the additional surface area and the potential for increased interference drag at the junction of the tank and the wing. Thus, while the induced drag can be decreased through better lift distribution, the total drag potential due to the additional structure can indeed increase.

Therefore, placing tip tanks on the wings will effectively increase drag potential while simultaneously contributing to a decrease in induced drag, which aligns with the provided answer.