Answer:
45 km/h
Step-by-step explanation:
In the first part of the trip, he already covered 30 km so we can subtract that from the total distance
45 - 30 = 15
This means he has 15 km to go
He also took an hour, or 60 minutes, to get to school. We subtract the time spent of the first part and time spent talking to a friend from the 60 minutes
60 - 35 = 25
25 - 5 = 20
He took 20 minutes to cover the second part of the journey
Speed = distance/time
15/20 = 0.75
He covered 0.75 km per MINUTE
to find it in km/h, we just multiply the number by 60
0.75 x 60 = 45
The answer is A your answer
Let's say her speed was x miles/hour during the first 3 miles runThen, time = distance/speedt1 = 3/x eq1 In the next 4 miles run, her speed = x-1 miles/hourTime taken:t2 = 4/(x-1) eq2 Now, total time:t1 + t2 = 1 3/5 hourssubstitute t1 and t2 from eqs. 1 and 2 3/x + 4/(x-1) = 1 3/5=> 3/x + 4/(x-1) = 8/5
=> 3(x-1) + 4x = 8x(x-1)/5=> 35x - 15 = 8x2 - 8x=> 8x2 - 43x + 15 = 0=> (8x-3)*(x-5) = 0=> x = 3/8 or 5 miles/hourx can not be 3/8 miles/hour because in that case, the speed during 4 miles run would be 3/8-1 = negative numberi.e. speed during 3 miles segment = 5 miles/hourand speed during 4 miles segment = 5-1 = 4 miles/hour
It's 34.
You can either intuitively know 25% means one-fourth and divide 136 by 4
Or
Convert the percentage to a decimal and multiply. 136 * 0.25 = 34
