Question

Lily is cutting a piece of yarn into 3 (three) pieces. The 2nd piece is 3 times as long as the 1st piece, while the 3rd piece is 6 centimeters longer than the 1st piece. When the yarn has a total length of 211 centimeters, calculate the length of the first piece.

Answer 1

Answer:

The length of the first piece = 41 cm

Step-by-step explanation:

Let the length of the first piece = a

Let the length of the second piece = b

Let the length of the third piece = c

we are given the following:

b = 3a . . . . . (1)     (The 2nd piece is 3 times as long as the 1st piece)

c = 6 + a  . . . . (2)    (the 3rd piece is 6 centimeters longer than the 1st piece)

a + b + c = 211 . . . . . (3)    (  the yarn has a total length of 211 centimeters)

Next, let us eliminate two variables, and this can easily be done by substituting the values of b and c in equations 1 and 2 into equation 3. this is done as follows:

a + b + c = 211

a + (3a) + (6 + a) = 211       ( remember that   b = 3a; c = 6 + a)

a + 3a + 6 + a = 211

5a + 6 = 211

5a = 211 - 6 = 205

5a = 205

∴ a = 205 ÷ 5 = 41 cm

a = 41 cm

Therefore the length of the first piece (a) = 41 cm

now  finding b and c

substituting a into equation 1 and 2

b = 3a

b = 3 × 41 = 123

∴ b = 123 cm

c = 6 + a

c = 6 + 41 = 47

∴ c = 47 cm