1. 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 documents?
2. A yacht sails 240 km in 4 hours and a speedboat sails 255 km in 3 hours. Find the ratio of the speed of the yacht to that of the speedboat.
Maths Question (F.2) =]
2007-08-28 7:24 pm
回答 (1)
2007-08-28 8:23 pm
✔ 最佳答案
1) to print 100 docs, it takes 420s & error will be 420s x 1/85 ~ 4.94s corr to 2 sig fighence, the possible range of time to print 1 doc will be
420.94/100 ~ 419.06/100
thus, the range will be from 4.1906s to 4.2094s
2) speed of yacht = 240/4 km/h = 60km/h
speed of speedboat = 255/3 km/h = 85km/h
the ratio of the speed of yacht to that of the speedboat = 60:85 = 12:17
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