Embercode: learn software engineering from zero

1. Predict the output of this code. ``

python
def page_time_ms(round_trips, rtt_ms, total_bytes, mbps):
    transfer_ms = total_bytes * 8 / (mbps * 1_000_000) * 1000
    return round_trips * rtt_ms + transfer_ms

print(f"{page_time_ms(40, 50, 40 * 2048, 10):.1f} ms")

`` What does the last line print?

2000.7 ms2065.5 ms2650.0 ms4065.5 ms

2. A page loads 40 small files one after another. The round-trip time is 50 ms. Which single change saves the most time?

Buy a 1000 Mbps line instead of a 10 Mbps lineShrink each file to 1 KBSend several of the requests at the same timeSplit each file into two halves

3. In the formula total time = round trips × RTT + bits ÷ bandwidth, the first part measures what? Answer with one word.

Type your answer.

4. Predict the output of this code. ``

python
import math

rtt = 90
files = 12
batch = 4
print(math.ceil(files / batch) * rtt, "ms in batches")
print(files * rtt, "ms one at a time")

`` What do the two lines print?

360 ms in batches, then 1080 ms one at a time270 ms in batches, then 1200 ms one at a time270 ms in batches, then 1080 ms one at a time1080 ms in batches, then 270 ms one at a time

5. How long does one round trip take, compared with the one-way latency?

About twice the one-way latencyAbout half the one-way latencyAbout the same as the one-way latencyAbout ten times the one-way latency

Latency math