Neco Model Questions Vol1 2023 Commerce Question 10

A company runs a communication campaign using two channels: social‑media posts and radio ads. Each social‑media post costs ₦5,000 and initially reaches 8,000 unique individuals; each subsequent post reaches 10\% fewer new individuals than the previous post (i.e., the second post reaches \(8{,}000\times0.9\), the third \(8{,}000\times0.9^{2}\), etc.). Each radio ad costs ₦20,000 and initially reaches 30,000 individuals; each additional radio ad reaches 5\% fewer new individuals than the previous ad. The campaign must reach at least 200,000 unique individuals. Determine the combination of social‑media posts and radio ads that meets or exceeds the target with the minimum total cost, and give the total cost and the total number of individuals reached.