If a point A(x,y) lies in the region bounded by the y-axis, straight lines 2y+x=6 and 5x−6y=30, then the probability that y<1 is :
(A)61
(B)65✓ Correct
(C)32
(D)76
Answer: (B)
Solution
The region is bounded by the y-axis (x=0), the line 2y+x=6, and the line 5x−6y=30.
Find the vertices: The lines 2y+x=6 and 5x−6y=30 intersect at B=(6,0). The line 2y+x=6 meets the y-axis at C=(0,3). The line 5x−6y=30 meets the y-axis at A=(0,−5).
The triangular region ABC has area 21×6×8=24.
The region where y<1 is bounded by y=1, which intersects 2y+x=6 at D=(4,1) and 5x−6y=30 at E=(536,1).
The area where y≥1 (triangle BDE) is 21×2×4=4.
Required probability =1−244=1−61=65.
JEE Main · 2022 · 27 Jun 2022 · Shift 2 · Single correct option