Okay guys,
I am here to ask you if you could please, please help me with figuring this out.
If you can help me in time, I may slide some forum cheese your way.
This needs to be figured out ASAP.

Jack's new telephone number, including the area code, forms a ten-digit number consisting of a pair of 1's separated by one digit, a pair of 2's separated by 2 digits, a pair of 3's and a pair of 4's, each separated by three digits, and a pair of 5's separated by five digits. Neither the sixth nor the ninth digit is a 4. What is Jack's telephone number?

Please help guys.

Thanks a lot.

435 243 2151

1 2 3 4 5 6 7 8 9 10

4 X X X 4 X X X X X
X 3 X X X 3 X X X X
X X 5 X X X X X 5 X
X X X 2 X X 2 X X X
X X X X X X X 1 X 1

6th number is 3, which isn't 4.
9th number is 5, which isn't 4.

the solution given by 'Kokua' is definitely meeting the description of the problems
now you have to check if it is the only one