Question 18
Three drainage pipelines have equal length. The first consists of one 16 dm section and some 11 dm sections. The second consists of three 14 dm sections, nine 13 dm sections, and some 11 dm sections. The third consists of fifteen 20 dm sections and some 30 dm sections. Each pipeline is between 370 dm and 400 dm long. How many 11 dm sections are used altogether?
