Question
Mathematics Question on types of differential equations
The number of natural numbers lying between 1012 and 23421 that can be formed using the digits 2, 3, 4, 5, 6 (repetition of digits is not allowed) and divisible by 55 is ____ .
Answer
The correct answer is 6
Case I: When number is 4-digit number (a b c d)
Here d is fixed and d=5
So, (a , b , c) can be (6, 4, 3), (3, 4, 6), (2, 3, 6), (6, 3, 2), (3, 2, 4) or (4, 2, 3)
⇒ 6 numbers
Case II: No number possible