I have tried 4x8x7x6. But i got incorrect all the time. Is my answer right or I am wrong? If I am wrong give me some hints.

@Gomuj @supro_v

The answer given in the question is correct. First don’t think about the 7000, cuz it will just create a mess. Then for the leftmost digit, you have 3 options: 4, 5 and 6. Then you will have 9 options for the second one, keep counting like that.

I hope you will find it.