What is the sum of natural numbers between 20 and 100  Choose the correct choice: A) 4800 B) 4860 C) 5000 D) 5500 E) 5550
a = first number   l = last number   Sn = n/2[a + l]   between 20 and 100 numbers = 81 =&gt; 100 - 20= 
<gadget id="calculator">100 - 20</gadget>
<output>80</output>
80 + 1= 
<gadget id="calculator">80 + 1</gadget>
<output>81</output>
81   Sn= 81/2 × 120 = 81 × 60 = 4860   4860)
<result>B</result>
What is the sum of natural numbers between 20 and 100