Question

how many numbers divisible by 5 can be formed from the digits 0,4,5,6,7&9 lying between 4000 and 5000.

Answer 1

Numbers can be formed,
1. if repetition is not allowed
= 1×3×2×1×2
= 12

2. If repetition is allowed
= 1×5×5×2
= 50
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Answer 2

There can be 2 cases.

When repetition is allowed,
1 x 5 x5 x2 = 50

When repetition not allowed
1 x3 x2 x 1 x2 = 12