If 21st and 22nd terms in the expansion of (1 + χ)44 are equal, then χ is equal to

1) 8/7

2) 21/22

3) 7/8

4) 23/24  

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Determine the coefficient of terms in the binomial expansion of (p+q)⁶?

6. What is the coefficient of I'y in the expansion of (x + y)'? Obtain a single number.