Q167 / 270 · NDA 2017 (Phase 2) · Mathematics
The number of terms in the expansion of $(x+a)^{100}+(x-a)^{100}$ after simplification is
- A$202$
- B$101$
- Correct answerC$51$
- D$50$
Solution
$(x+a)^{100}+(x-a)^{100}$
Simple logic is we get ${ }^n c_0,{ }^n c_2,{ }^n c_4 \ldots .{ }^n c_{100}$ in this expansion.
The number of terms from $\mathrm{n}_{\mathrm{c}_0}$ to $\mathrm{n}_{\mathrm{c}_{100}}$ are 51
$\therefore$ There are 51 terms.
Hence, the correct answer is option: 'C'.