Number of permutations of 1,2,3,4,5,6,7,8, and 9 taken all at a time are such that digit 1 appearing somewhere to the left of 2 and digit 3 appearing to the left of 4 and digit 5 somewhere to the left of 6 , is
(e.g.815723946 would be one such permutation)
Number of digits are 9
Select 2 places for the digit 1 and 2 in ways
from the remaining 7 places, select any two places for 3 and 4 in ways and from the remaining 5 places select any two for 5 and 6 in ways.
Now, the remaining 3 digits can be filled in 3! ways.
Total ways
Study 40% syllabus and score up to 100% marks in JEE