Question

A carpenter wishes to make a ladder with 15 cross-pieces.The cross-pieces are to diminish uniformly in Lengths from 67cm at the bottom to 32cm at the top.
Calculate the Length,in cm,of the 7th cross-piece from the bottom.
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Answer 1

Answer:

52 cm

Step-by-step explanation:

1st piece (from bottom) = 67 cm

15th piece = 32 cm

a = 67

a₁₅ = a + 14d = 32

14d = 32 - 67

d = -35/14

d =-5/2

d = -2.5

a₇ = a + 6d

= 67 + 6(-2.5)

= 67 - 15

= 52 cm