AP EAMCET202421 May 2024Evening ShiftMathematicsProbabilityActual
If two numbers x and y are chosen one after the other at random with replacement from the set of number 1,2,3 ..., 10 , then the probability that |x^2-y^2 | is divisible by 6 is
Options
- A8 25
- B6 25
- C3 10
- D13 50
Correct answer
C. 3 10
Step-by-step solution
Total number of ways in which two numbers can be selected from 1,2,3, ., 10 =10^2 |x^2-y^2 | is divisible by 6 |(x-y)(x+y)| is divisible by 6 either (x-y) is divisible by 6 or (x+y) is divisible by 6 . So, possible outcomes are array |c|c|c| Values of x & Values of y & No. of cases 1 & 1,5,7 & 3 2 & 2,4,8,10 & 4 3 & 3,9 & 2 4 & 4,2,8,10 & 4 5 & 5,1,7 & 3 6 & 6 & 1 7 & 7,1,5 & 3 8 & 8,2,4,10 & 4 9 & 9,3 & 2 10 & 10,4,2,8 & 4 & & 3 0 array Required probability = 30 10^2 = 3 10 .