Question

Every day at noon, a bus leaves for Townville and travels at a speed of x kilometers per hour. Today, the bus left 30 minutes late. If the driver drives 7/6 times as fast as usual, she will arrive in Townville at the regular time. If the distance to Townville is 280 kilometers, what is the value of x

Answer 1

Answer:

Step-by-step explanation:

Given that every day at noon, a bus leaves for Townville and travels at a speed of x kilometers per hour. Today, the bus left 30 minutes late.

If the driver drives 7/6 times as fast as usual, she will arrive in Townville at the regular time.

If correct time leaves then distance = time *speed

280 = t*x where t is the time in hours

Or t = 280/x

Now speed changes to 7x/6 while time changes to (t-1/2)

So 280 = (t-1/2) 7x/6

$280 = (\frac{280}{x} -\frac{1}{2} )(\frac{7x}{6} )\\240= (\frac{280}{x} -\frac{1}{2} )x\\\\x=80$

x = 80 km per hour