A carpenter cuts of from a plank 5/12 of its length and then 6/7 of what remains. Of the remaining piece is 2/1/2 m long. find the original length of the plank

Question

Mathematics

Ronnie Hebert

6 November, 10:46

A carpenter cuts of from a plank 5/12 of its length and then 6/7 of what remains. Of the remaining piece is 2/1/2 m long. find the original length of the plank

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Abbigail Rasmussen · Answer 1

Cut 5/12 of his lenght

remain 7/12 of his lenght

7/12*L - 6/7 * 7/12*L=2 1/2 m

7/12*L (1-6/7) = 7/12*L (7/7-6/7) = 7/12*L*1/7=L/12 = 2 1/2

⇒L=2 1/2 m * 12=5/2*12=30 m

Original length was 30 m