Kangaroo Jump Logic

Question

There are two kangaroos on a number line ready to jump in the positive direction (i.e, toward positive infinity). The first kangaroo starts at location x1 and moves at a rate of v1 meters per jump. The second kangaroo starts at location x2 and moves at a rate of v2 meters per jump. Given the starting locations and movement rates for each kangaroo, can you determine if they'll ever land at the same location at the same time?

if x1=0, v1= 5, x2=4, v2=4

Answer 1

public String kangaroo(int x1, int v1, int x2, int v2)
{
// Complete this function
String ans = "";
if(v1 > v2 && ((x2-x1)%(v1-v2) == 0))
{ ans ="YES";}
else
{ ans ="NO";}
return ans; }

Answer 2

i am giving a general solution :::
x1+(v1*t)=x2+(v2*t)
//bcz distance in +ve x-dir & time taken will be same for both
on putting values we get t=4 sec ,
ie they will meet first @ t=4sec at dist. 20 m from the origin