The cost to rebuild Nepal after its most devastating earthquake in eight decades will exceed $10 billion and take years, Finance Minister Ram S. Mahat said. “We have reason to believe that there are survivors in the rubble but we don’t have equipment to deal with the situation,” Mahat said at his office in the capital of Kathmandu. His reconstruction estimate is equivalent to about half of Nepal’s $20 billion economy, which is smaller than all 50 U.S. states. Heavy rains in Kathmandu on Tuesday impeded efforts to find any remaining survivors.