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← JEE Main 2017 · 2 Apr · Shift 1
MathematicsSingle correct+4 / -1Question 87 of 90

JEE Main 2017 · 2 Apr · Shift 1, Mathematics question 87

If two different numbers are taken from the set {0, 1, 2, 3, ......, 10}; then the probability that their sum as well as absolute difference are both multiple of 4, is :

Choose one option
Answer and worked solution

Official answer: D

Both x+yx+y and x−yx-y divisible by 4 means x≡y(mod4)x\equiv y\pmod4 and xx even. The pairs come from {0,4,8}\{0,4,8\} (3 pairs) and {2,6,10}\{2,6,10\} (3 pairs). Out of (112)=55\binom{11}2=55 pairs: 655\frac6{55}.