Vehicle meeting calculation

A car departs from place A at 1:00 PM at a speed of 72 km/h. At the same time, a truck departs from point B toward A at a speed of 68 km/h. Point B is 315 km from A. When and where will they meet?

Result

t = 15:15 hh:mm
s₁ =  162 km

Step-by-step explanation:

$$\begin{gathered} s_1+s_2=s \\ {v}_1=72\text{km/h} \\ {v}_2=68\text{km/h} \\ s=315\text{km} \\ {v}_1\cdot x+v_2\cdot x=s \\ 72\cdot x+68\cdot x=315 \\ 140x=315 \\ x=\frac{315}{140}=2.25 \\ x=\frac{9}{4}=2.25 \\ t=x+13.00=2.25+13.00=15.25=15:15\text{hh}:\text{mm} \end{gathered}$$

$s_1=v_1\cdot x=72\cdot 2.25=162\text{km}$

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