Explanation

(d)
Using the digits 0, 1, 2, …… ,9 the number of five digits telephone numbers which can be formed is $10^{5}$(since repetition is allowed).
The number of five digits telephone numbers, which have none of digits repeated $= \ ^{10}P_{5} = 30240$
$\therefore$ The required number of telephone number
$= 10^{5} - 30240 = 69760$