Question

Find the sum of all natural numbers from 1 to 100 which are not multiples of 4.​

Answer 1

Answer:

3750

Step-by-step explanation:

For the sum of all numbers from 1 to 100:

 Using the properties of AP: In this AP, a = 1, d = 1, l = 100

So there are 100 terms, hence sum of all of these numbers is:

⇒ (n/2) [ a + l ]

⇒ (100/2) ( 1 + 100 ) ⇒ 50( 101 )

⇒ 5050

For the sum of all number from 1 to 100( which have 4 as factor ):

 In this AP, a = 4, d = 4, l = 100, let there n terms

⇒ nth term = a + ( n - 1 )d  { formula}

⇒ 100 = 4 + ( n - 1 )4

⇒ 96/4 = n - 1

⇒ 24 = n - 1    ⇒ 25 = n

Hence,

⇒ their sum = (25/2)( 4 + 100 )

            = (25/2)( 104 )

            = 1300

Hence,

⇒ sum of numbers which are not multiples of 4:

⇒ 5050 - 1300

⇒ 3750

Answer 2

Answer:

3750 is the correct answer please make as braniist