Question

How many odd numbers with 4 different digits, can be formed using the digits 1, 2, 3, 4, 5, 6, 7, 8? (No repetition is allowed)

A. 71
B. 200
C. 210
D. 840
E.1680

Answer 1

840 ( D )

Explanation:

GIVEN DIGITS : 1,2,3,4,5,6,7,8

Number of odd numbers = 4

Number of even numbers = 4

therefore the number of odd numbers with 4 different digits can be formed by the same way the number of even numbers ( without repetition )

Hence the number of ways odd numbers with 4 different digits = Total number of ways of forming 4 digit numbers / 2

8*7*6*5 = 1680 / 2 = 840 ways