Question 144057
let the number be abcde
d=b+1
a=2b-1
so b<=5
b+c=10
so c=10-b
a+d+e=20
so 2b-1+b+1+e=20
3b+e=20
e=20-3b
so e=5 or 8 because b<=5 
If e=5 then b=5
If e=8 then b=4
a+b+c+d+e=30
Try e=5: 2b-1+b+10-b+b+1+5=30
3b+15=30
3b=15
b=3 wrong
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Try e=8: 2b-1+b+10-b+b+1+8=30
3b+18=30
3b=12
b=4 OK so far.
a=7
c=6
d=5
7+4+6+5+8=30
7+5+8=20
74658 is the number
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Ed