Question

what number is that third part exceeds fifth part by 4

Answer 1

let number be x.
third part of the no.=x/3
fifth part of the no.=x/5
According to condition
x/3-x/5=4.
LCM=15
5x-3x/15=4
2x/15=4
x=4*15/2.
hence no.=30...
     :)

Answer 2

let the no. be X
then the third part is X/3
and fifth part is X/5
according to problem
X/3-X/5=4
LCM of the numerators is 15
5x-3x/15=4
2x/15=4
X=4*15/2
X=30

hence the number is 30