WBJEE · Maths · Permutation Combination
The digit in the unit's place of the number \(1 !+2 !+3 !+\ldots \ldots \ldots+99 !\) is
- A 3
- B 0
- C 1
- D 7
Answer & Solution
Correct Answer
(A) 3
Step-by-step Solution
Detailed explanation
\(1+2+6+24\) \(\quad\quad\quad\)unit digit is zero \(=33\) \(\therefore\) Unit digit = 3
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Maths
- Let \(f:[1,3] \rightarrow R\) be a continuous function that is differentiable in (1,3) an \(f^{\prime}(x)=|f(x)|^{2}+4\) for all \(x \in(1,3).\) Then,WBJEE 2019 Medium
- A variable line passes through a fixed point \(\left(x_{1}, y_{1}\right)\) and meets the axes at \(A\) and \(B\). If the rectangle \(O A P B\) be completed, the locus of \(P\) is, \((O\) being the origin of the system of axes).WBJEE 2019 Medium
- Let \(f(x)=\max \{x+|x|, x-[x]\}, \quad\) where \(\quad \mid x]\) denotes the greateat integer \(\leq x\). Then, the value of \(\int_{-3}^{3} f(x) d x\) isWBJEE 2014 Easy
- Let \(\mathrm{f}(\mathrm{x})=\tan ^{-1} \mathrm{x}\). Then \(\mathrm{f}^{\prime}(\mathrm{x})+\mathrm{f}^{\prime \prime}(\mathrm{x})\) is \(=0\), when \(\mathrm{x}\) is equal toWBJEE 2011 Hard
- If the volume of the parallelopiped with \(\vec{a} \times \vec{b}, \vec{b} \times \vec{c}\) and \(\vec{c} \times \vec{a}\) as coterminous edges is 9 cu. units., then the volume of the parallelopiped with \((\vec{a} \times \vec{b}) \times(\vec{b} \times \vec{c}),(\vec{b} \times \vec{c}) \times(\vec{c} \times \vec{a})\) and \((\vec{c} \times \vec{a}) \times(\vec{a} \times \vec{b})\) as coterminous edges isWBJEE 2023 Medium
- Let \(\Delta=\left|\begin{array}{ccc}\sin \theta \cos \phi & \sin \theta \sin \phi & \cos \theta \\ \cos \theta \cos \phi & \cos \theta \sin \phi & -\sin \theta \\ -\sin \theta \sin \phi & \sin \theta \cos \phi & 0\end{array}\right|\). ThenWBJEE 2022 Hard
More PYQs from WBJEE
- How many monobriminated product(s) (including stereoisomers) would form in the free radical bromination of nbutane?WBJEE 2022 Easy
- The ground state electronic configuration of CO molecule isWBJEE 2013 Medium
- The eccentric angle in the first quadrant of a point on the ellipse \(\frac{x^{2}}{10}+\frac{y^{2}}{8}=1\) at a distance 3 units from the centre of the ellipse isWBJEE 2012 Easy
- If \(\lim _{x \rightarrow 0} \frac{a x e^{x}-b \log (1+x)}{x^{2}}=3\) then the values of \(a\) and \(b\) are, respectivelyWBJEE 2015 Easy
- An electric cell of emf \(E\) is connected across a copper wire of diameter \(d\) and length \(l\). The drift velocity of electrons in the wire is \(v_{d}\). If the length of the wire is changed to \(2 l,\) the new drift velocity of electrons in the copper wire will beWBJEE 2013 Easy
- The length of a metal wire is \(L_{1}\) when the tension is \(T_{1}\) and \(L_{2}\) when the tension is \(T_{2}\) The unstretched length of wire isWBJEE 2015 Medium