Question

A construction worker welded 3 pipes of length 2 m 10 cm each together. This new pipe was only 3/5 of the length he needed. How long was the pipe he needed?

Answer 1

L = pipe length

2 m 10 cm = 2.1 m

3 ∙ 2.1 = 6.3 m

This new pipe was only 3/5 of the length he needed means:

6.3 = 3 / 5 L

Multiply both sides by 5

31.5 = 3 L

L = 31.5 / 3

L = 10.5 m

Answer 2

length of 3 pipes = 2 m 10 cm + 2 m 10 cm + 2 m 10 cm = 6 m 30 cm = 630 cm
Let x cm pipe was needed
According to questions,
x * 3/5 = 630
x = 630 * 5/3
= 210 * 5
= 1050 cm
= 10 m 50 cm
Answer: 10 m 50 cm