Question
Andy and Mark take 6 days to assemble a toy train. Mark and Charlie take 3 days to build the same train while Andy and Charlie take only 5 days. How many complete days would the three of them take to build the same toy train?
4 m

Click button first when a symbol is required. X

Andy and Mark take 6 days to assemble a toy train. Mark and Charlie take 3 days to build the same train while Andy and Charlie take only 5 days. How many complete days would the three of them take to build the same toy train?