Question

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-m apart, what is the length of the wood required for the rungs?
See the given figure. ​

Answer 1

Answer:

So,

Total no. of rings : 5/2/25 = 250/25 = 10

(Divide the total distance which is 5/2 with the distance between to consecutive rings)

So, there are total 10 rings

The lenght of the wood required is = Sum of 10 rungs

=) sn= n/2{a + l}

=) n= 10 , a=25 and L= 45

substitute the values and,

= 10/2 (25 + 45)

=5*70 = 350cm

Hence the Answer is 350 cm

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Peace!