Bengaluru-based startup Chimple, which builds tablet-based solutions to help children learn better, has advanced to semi-finals of the $15 million (₹97 crore) Global Learning XPrize, backed by Elon Musk. The 11 semi-finalists, selected from a field of 198 teams, are competing to make software that will let children in developing countries teach themselves basic reading and arithmetic in 15 months.