Question

Two cars,X travelling at an average speed of 40 km/hr and Y travelling at an average speed of 50km/hr start from the same point at the same time.If they travel in opposite directions ,how far apart will they be after half an hour?​

Answer 1

Answer:

45 km apart

Explanation:

X speed = 40 km/hr =  $\frac{40km}{hr}$

Y speed = 50 km/hr = $\frac{50km}{hr}$

Time given = 1/2 hr = $\frac{1hr}{2}$

Distance traveled = speed(s) x time(t)

Since X and Y traveled in opposite directions, we can say X went West and Y went East.

On a number line, X will be represented as - and Y as +

First, to calculate distance of X = $\frac{40km}{hr} *\frac{hr}{2}$

                                                X = 40 km/2

                                                X = 20 km (remember '-' sign)

To calculate distance of Y = $\frac{50km}{hr} *\frac{hr}{2}$

                                        Y = 50 km/2

                                        Y = 25 km

Distance apart = distance difference=25 km - (-20 km)

                                                            =25 km + 20 km

                                                            =45 km

Answer 2

Answer:

45km

Explanation:

x speed = 40 km/hr = \frac{40km}{hr}

hr

40km

Y speed = 50 km/hr = \frac{50km}{hr}

hr

50km

Time given = 1/2 hr = \frac{1hr}{2}

2

1hr

Distance traveled = speed(s) x time(t)

Since X and Y traveled in opposite directions, we can say X went West and Y went East.

On a number line, X will be represented as - and Y as +

First, to calculate distance of X = \frac{40km}{hr} *\frac{hr}{2}

hr

40km

∗

2

hr

X = 40 km/2

X = 20 km (remember '-' sign)

To calculate distance of Y = \frac{50km}{hr} *\frac{hr}{2}

hr

50km

∗

2

hr

Y = 50 km/2

Y = 25 km

Distance apart = distance difference=25 km - (-20 km)

=25 km + 20 km

=45