Answer:
40 barrels
Explanation:
Given that:
Let x = number of minutes
Old conveyor line :
Filling rate = 3 barrels per minute
Already filled = 10 barrels
Equation :
10 + 3x - - - (1)
NEW conveyor line:
Filling rate = 4 barrels per minute
Equation :
4x - - - (2)
Equate equation (1) and (2)
10 + 3x = 4x
10 = 4x - 3x
10 = x
Hence, in 10 minutes, each line will have filmed same number of barrels which is
4x = 4*10 = 40 barrels
10 + 3x = 10 + 3(10) = 40 barrels