Answer:
BC= 3
Explanation:
Suppose a line BD is 10 and it has a point C somewhere on the line. It is given that BC is 3times and CD is 7 times or algebraically if we take x as a variable then according to the given information
BC+ CD= BD
3x+ 7x= 10
10x= 10
x= 10/10
x= 1
3x would give 3 (1)= 3
Hence the Line BC = 3
and the line CD= 7