Warning: this strategy may not align with your ethical viewpoints; however, I believe that this business model is feasible and can be profitable.
Arbitrage involves taking advantage of price differences of a certain product or service in different markets while the price differences still exist. By buying it in a market where the price is low, and then selling it in a market where it is valued at a higher price, one can easily and quickly make a profit. Usually such opportunities don't last very long, as the markets tend to reach equilibrium due to trading. However, this is not always the case for services. One avenue for arbitrage that has existed for years (and will continue to exist for years) is the difference in valuation of solutions to homework problems and exams in different parts of the world. Although there are a few existing services that outsource homework and test problems already, they are unreliable and poorly set up due to a diffused focus on personnel management.
The difference in valuation described above is the result of variations around the globe in many parameters - costs of investment required for good schooling; levels of student competitiveness and capabilities; the buying power of a given sum of money etc. Education costs in the US are much higher than in India, the number of people in the US who can provide answers is lower, and the buying power of a given sum is significantly higher in India than in the US. In the article "Strategies That Fit Emerging Markets", Khanna et al suggest that a company interested in international markets should analyze the country's institutional context. Based on this analysis, the company should adjust its strategy accordingly .
In the case of India, I suggest creating or adapting a business model that capitalizes on the educated Indian labor market. The Indian labor market consists of a sufficiently large number of well-educated yet poorly compensated (relative to US income standards) graduates. A large number of them understand English, thanks to the large number of English-medium schools in India. Additionally, the intense competition among students in India results in many qualified graduates. Under the Modi administration, top-level corruption of government officials has been significantly curbed, and India's openness to international companies willing to invest in Indian talent has increased. The "Make in India" initiative is reflective of this change in outlook. These factors all support launching this business with service centers in India. However, one area of concern pointed out by Khanna et al is the power of trade unions in India. To avoid this hurdle, I suggest that respondents are rewarded and rated on an individual basis, based on the quantity and quality of their submitted answers. This will leverage the competitiveness prevalent in the Indian labor market and prevent powerful trade unions from forming. To ensure that this business can reliably deliver results, talented local managers will be required to delegate tasks and incentivize performance among known top respondents. Additionally, given the rapid increase in low-cost mobile broadband connectivity in India and the influx of economical smartphones from Chinese manufacturers, this company will likely rely solely on human capital. This allows for reduced service costs, as this business will not require a dedicated physical infrastructure setup.
 Khanna, T., Palepu, K., and Sinha, J., Strategies That Fit Emerging Markets, Harvard Business Review, June 2005