Question

Find the sum of all 3 digit numbers that are divisible by 4. ​

Answer 1

=> The smallest 3 digit number divisible by 4 is 100 while the largest is 996.

=> The sum of all 3 digit numbers divisible by 4 is an exercises is an AP.

=> a = 100 , d = 4,

=> 996 = a + ( n - 1 ) d = 100 + ( n - 1 ) × 4, or

=> 249 - 25 = 225 = ( n - 1 )

=> n = 225

=> S225 = ( 225/2 ) [ 2 × 100 + ( 255 - 1 ) × 4 ]

=> ( 225/2 ) [ 200 + 896 ]

=> ( 225/2 ) × 1096

=> 123300

I hope this will help you dear..

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