WBJEE · Maths · Probability
Three numbers are chosen at random from 1 to 20 . The probability that they are consecutive is
- A \(\frac{1}{190}\)
- B \(\frac{1}{120}\)
- C \(\frac{3}{190}\)
- D \(\frac{5}{190}\)
Answer & Solution
Correct Answer
(C) \(\frac{3}{190}\)
Step-by-step Solution
Detailed explanation
Hints: Total number of cases ; \({ }^{20} \mathrm{C}_3=\frac{20 \times 19 \times 18}{2 \times 3}=20 \times 19 \times 3=1140\) Total number of favourable cases \(=18\) \(\therefore\) Required probability \(=\frac{18}{1140}=\frac{3}{190}\)
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
- From a balloon rising vertically with uniform velocity \(\mathrm{ft} / \mathrm{sec}\) a piece of stone is let go. The height of the balloon above the ground when the stone reaches the ground after \(4 \mathrm{sec}\) is \(\left[\mathrm{g}=32 \mathrm{ft} / \mathrm{sec}^2\right]\)WBJEE 2022 Easy
- Tangents are drawn to the ellipse \(\frac{x^{2}}{9}+\frac{y^{2}}{5}=1\) at the ends of both latusrectum. The area of the quadrilateral, so formed isWBJEE 2017 Medium
- The locus of points \((x, y)\) in the plane satisfying \(\sin ^2 x+\sin ^2 y=1\) consists ofWBJEE 2023 Hard
- If \(\left(1-x+x^2\right)^n=a_0+a_1 x+\ldots . .+a_{2 n} x^{2 n}\), then the value of \(a_0+a_2+a_4+\ldots \ldots .+a_{2 n}\) isWBJEE 2010 Hard
- The number of permutations by taking all letters and keeping the vowels of the word COMBINE in the odd places isWBJEE 2010 Medium
- Let each of the equations \(x^{2}+2 x y+a y^{2}=0 \& a x^{2}+2 x y+y^{2}=0\) represent two straight lines passing through the origin. If they have a common line, then the other two lines are given byWBJEE 2020 Medium
More PYQs from WBJEE
- If \(x=\log _a b c, y=\log _b c a, z=\log _c a b\), then the value of \(\frac{1}{1+x}+\frac{1}{1+y}+\frac{1}{1+z}\) will beWBJEE 2009 Medium
- A point object is placed on the axis of a thin convex lens of focal length \(0.05 \mathrm{m}\) at a distance of \(0.2 \mathrm{m}\) from the lens and its image is formed on the axis. If the object is now made to oscillate along the axis with a small amplitude of \(A \mathrm{cm},\) then what is the amplitude of oscillation of the image? \(\left[\right.\) you may assume, \(\frac{1}{1+x} \approx 1-x,\) where \(\left.x< < 1\right]\)WBJEE 2019 Hard
- Four equal charges of value \(+Q\) are placed at four vertices of a regular hexagon of side
W. By suitably choosing the vertices, what can the maximum possible magnitude of electric field at the centre of the hexagon?WBJEE 2018 Medium - A double ordinate \(\mathrm{PQ}\) of the hyperbola \(\frac{\mathrm{x}^{2}}{\mathrm{a}^{2}}-\frac{\mathrm{y}^{2}}{\mathrm{~b}^{2}}=1\) is such that \(\Delta \mathrm{OPQ}\) is equilateral, \(\mathrm{O}\) being the centre of the hyperbola. Then the eccentricity e satisfies the relationWBJEE 2020 Easy
- If \(\vec{\alpha}=3 \vec{i}-\vec{k},|\vec{\beta}|=\sqrt{5}\) and \(\vec{\alpha} \cdot \vec{\beta}=3\), then the area of the parallelogram for which \(\vec{\alpha}\) and \(\vec{\beta}\) are adjacent sides isWBJEE 2025 Medium
- In the following compound, the number of sp-bybridised carbons are
WBJEE 2015 Medium