Question

A student has to answer $10$ questions, choosing at least $4$ from each of the parts $A$ and $B$. If there are $6$ questions in part $A$ and $7$ in part $B$, then the number of ways can the student choose $10$ questions is

• A. 256
• B. 352
• C. 266
• D. 426

Answer 1

Answer: (C)

${}^{13}{C}_{10}-{}^6{C}_3=286-20=266$