NET JRF PART - A : Questions and Solutions : NET JUNE-2018

NET JRF PART - A : Questions and Solutions:

NET JUNE-2018

1.) What is the value of ( 1 + 3 + 5 + 7 + ...... +  4033 ) + 7983 × 2017 ? 

 (a) 20170000 (b) 20172017 (c) 20171720 (d) 20172020

Ans. : (a) 20170000 .

Solution: 

1 + 3 + 5 + 7 + ....... + 4033 = ?

Hence, ( 2n - 1 ) = 4033

 2n - 1 = 4033

2n = 4033 + 1

2n = 4034

n = 4034/2

n = 2017 .

n² = n × n = 2017 × 2017 = 4,068,289 .

1 + 3 + 5 + 7 + ....... + 4033 = 4,068,289 .

( 1 + 3 + 5 + 7 + ...... +  4033 ) + 7983 × 2017 = 4,068,289 + 7983 × 2017 

= 4,068,289 +16,101,711 = 20170000.