Acar travels at a speed of 80 km/h for 2½ hours from town p to town q. then the car increases its speed by 25% and maintains that speed for a further 150 km from town q to town r. calculate the average speed for the whole journey.

So this is not too hard, as with any math problem we write what we know.

Starting speed: 80km/h
Time from P to Q: 2.5h
Increase in speed: 20km/h (25% is dividing by 4)
Distance from Q to R: 150 kilometers

So let's find the speed and distance for both legs of the trip.

Speed for P to Q: 80km/h
Distance from PtoQ: 200km (2.5h * 80km/h)
Speed from Q to R: 100km/h (80 +20)
Distance from QtoR: 150km.

Now we multiply the speeds by their respective distances add them and then divide by the total distance.

((80 *200) + (100 * 150))/350 = ~88.57143

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116

i only know the sequence of arithmetic it adds the first is 5+4 then it goes up as it adds to then it is 9+5 then 14+6 then to 20+7 and so on. 5,9,14,20,27,35.

step-by-step explanation: