1.

Find the sum of all numbers between 300 and 500 which are divisible by 7.

Answer»

Answer:

Step-by-step explanation:

Hey,sup!

We'll solve this USING Arithmetic Progression.

As PER the QUESTION,

a=308. (First NUMBER divisible by 11 in the range)

d= 11.

l=495. (Last number divisible by 11 in the range)

A(n)= a+(n-1)d.

=>495=308+(n-1)11.

=>495-308=(n-1)11.

=>187=(n-1)11.

=>n-1= 187/11= 17.

=> n= 17+1 =18.

S(n)= n/2 (a+l).

S(18)= 18/2(308+495).

= 9 × 803.

= 7227.

Sum of all natural numbers between 300 and 500 which are divisible by 11 is 7227.

Hope it helps ya...

#Pari here...


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