A starts from X at 9:00 am and reaches Y at 1:00 pm.
B starts from Y at 9:00 am and reaches X at 3:00 pm.
What time do the two meet?
So we can see that,
9am ----> 1pm is 4 hrs
9am ----> 3pm is 6 hrs
Now I am stuck how to assume the total distance then speed. With the concepts I know Distance = Speed * Time
How to find the combined speed if I at least assume the distance as 100?
If I am not wrong I have to consider calculating the relative speed.
Suppose speeds are constant and the distance between $X$ and $Y$ is $1$ unit. Then $v_A = 1/4$ and $v_B = 1/6$. The distance measured from $X$ is given by $$ d_A = \frac{1}{4}t,\quad t\leqslant 4,\quad\mbox{and}\quad d_B = 1-\frac{1}{6}t,\quad t\leqslant 6. $$ For some $t_0\leqslant 4$, the two quantities are equal. Find $t_0$.