A Ladder has rungs 25 cm apart The rungs decrease uniformly in length from 45 cm at the bottom to - Maths - Triangles

Question

A Ladder has rungs 25 cm apart The rungs decrease uniformly in
length from 45 cm at the bottom to 25 cm at the top If the top and
the bottom rungs are 2 1/2 m apart, what is the length of th wood
required for the rungs?

Aakash Sharma · Accepted Answer

Dear Student!

Here is the answer to your query.

It is given that the gap between the consecutive rungs is 25 cm and the top and bottom rungs are 2.5 m i.e., 250 cm apart.

∴ Number of rungs $= \frac{250}{25} = 10$

Now rungs decrease uniformly in length from 45 cm at the bottom to 25 cm at the top.

∴ The length of the rungs forms an A.P. with first term (a) = 45 m and 10^th term = 25 cm

∴ Length of the wood required for rungs = sum of 10 terms of the A.P.

$= \frac{10}{2} (45 + 25) cm [∵ S_{n} = \frac{n}{2} (a + l)] = 350 cm = 3.5 metres$

Cheers!

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A Ladder has rungs 25 cm apart.The rungs decrease uniformly in length from 45 cm at the bottom to 25 cm at the top. If the top and the bottom rungs are 2 1/2 m apart, what is the length of th wood required for the rungs?