The sum of even coefficients in the expansion of (1+X)⁷ is.....

Answer 1

0

zero

all coefficients are odd

1,7, 21. 35. 35. 21. 7. 1

unless maybe you meant "even" in the sense of 2nd, 4th, 6th coefficients & 8th ?

then 7+35+21 +1 = 64