QJEEM19Ma24ec: JEE Main 2019 Mathematics - Class 11 JEEM19Ma24ec Solution: The number of natural numbers less than 7,000 which can be…

Total no 1 digit numbers possible = 4 (allowed digits 1, 3, 7, 9)

Total no 2 digit numbers possible = 4$$\times$$5 = 20

Total no 3 digit numbers possible = 4$$\times$$5$$\times$$5 = 100

Total no 4 digit numbers possible = 2$$\times$$5$$\times$$5$$\times$$5 = 250

So the number of natural numbers less than 7,000 possible are
= 4 + 20 + 100 + 250 = 374