approximation & errors Q&A

a few questions wanna ask.Please ans it in STEP.thanks for helping!!





Q1. The time taken by a train to go from station A to station B is 3 min 49s.
Express the time in seconds,correct to 2 significant figures.



Q2. Estimate the value of the numerical expression 308.8 - 5.9513 / 0.02038
by first rounding off each number to 1 significant figure.



Q3. The number of heartbeats per min of a humming - bird measured by a
biologist is 980, and the relative error is 1/245.What is the possible range of
the number of heartbeats per min.?



Q4. By using a stop-watch,Peter finds that the time taken for a colour printer to
print 100 identical documents is 7 minutes 5 seconds, and the relative
error is 1/85.What is the possible range of time required to print 1 document?



Q5. The maxinum pulling strength of a fishing - line measured by a laboratory is
60 kg and the percentage error is 5%.What is the possible range of the
maxinum pulling strength of the fishing - line?



Q6. The time required for an anti- virus software to scan all the files of the
computer is measured by a programmer to be 19 minutes 15 second,
correct to the nearest 5 seconds. Find the percentage error of the
measured time correct to 2 significant figures.



Q7. An observatory records that the Leo meteor shower appears every 33 years,
correct to the nearest 0.5 year, and the Halley's comet returns every 76
years,correct to the nearest year.



Q7(a). Find the percentage error for each of these recorded time, correct to 2
significant firgures.



Q7(b). Compare the two recorded time to find out which one is more accurate.



Q8. Given a four - digit odd number which is greater than 9000 and is divisible by
13. When rounded off to 3 significant firgures, it is divisible by 4. When
rounded off to 2 significant firgures, it is divisible by 11. Find the number.



Remember to put steps~ Thanks guys!!