Answer:
$800 million more
Step-by-step explanation:
Amount spent each year under the government wheat price-support program = $0.2 × 10 billion = $2 billion
Amount spent each year in an unregulated market for Pakistani wheat = $0.1 × 12 billion = $1.2 billion
Amount spent more each year under the government wheat price-support program than otherwise would have been spent in an unregulated market = $2 billion - $1.2 billion = $800 million