Mark the correct alternative in the following:

The value of is


( 7C0 + 7C1 ) + ( 7C1 + 7C2 ) + ( 7C2 + 7C3 ) + ( 7C3 + 7C4 ) + ( 7C4 + 7C5 ) + ( 7C5 + 7C6 ) + ( 7C6 + 7C7 )


= 1 + 27C1 + 27C2 + 27C3 + 27C4 + 27C5 + 27C6 + 1


= 1 + 27C1 + 27C2 + 27C3 + 27C3 + 27C2 + 27C6 + 1 ⇒ (7C3 = 7C4 and 7C2 = 7C5)


= 2 + 22 (7C1 + 7C2 + 7C3)


= 2 + 22 (7 + 6 + 5)


= 2 + 252


= 254


= 28 – 2

1