a student can memorize words at a rate of m(t)=3t(3t^2+1)^ -1/2 words per minute, where t is in minutes?
414104
Using an integral,\n\nWords = S 3t(3t^2 + 1)^(-1/2) dt\n\nlet u = 3t^2 + 1\nthen du = 6t dt\n\n= (1/2) S u^(-1/2) du\n= (1/2)(2u^(1/2))\n= u^(1/2)\n= (3t^2 + 1)^(1/2)\n\nEvaluating from 1 to 4,\n= (3(4)^2 + 1)^(1/2) - (3(1)^2 + 1)^(1/2)\n= 49^(1/2) - 4^(1/2)\n= 7 - 2\n= 5\n\nAnswer A.
1129645
Practice makes perfect! You only need to concentrate on your presentation for tomorrow. Short term memory is not the problem. Go on! You can do that!\n:)
870276
bdenton2k is right. Also to use mnemonics.\n\nHere are some links that you may want to refer to:\n\n1) http://www.memletics.com/manual/mnemonics.asp\n2) http://www.fun-with-words.com/mnemonics.html\n3) http://www.coun.uvic.ca/learn/program/hndouts/mnemon.html
604162
Typing\n\nAs of 2005, Barbara Blackburn is the fastest typist in the world, according to The Guinness Book of World Records. \n\nUsing the Dvorak Simplified Keyboard, she has maintained 150 word/min for 50 min, 170 word/min for shorter periods of time, and has been clocked at a peak speed of 212 word/min. Blackburn failed her typing class in high school, first encountered the Dvorak keyboard in 1938, quickly learned to achieve very high speeds, and occasionally toured giving speed-typing demonstrations during her secretarial career.\n\n\n\n\nReading\n\nEducated adults read at 200-350 wpm, at best 400 wpm for full comprehension. Research has shown that speed reading at 600 wpm can achieve about 70% comprehension, and 50% comprehension at 1000 wpm.\n\n\nSpeech\n\nBooks on tape are 150-175 words per minute, slide presentations tend to be closer to 100 wpm. Conversations are around 200 wpm, and although research by Ronald Carver has demonstrated that while adults can listen with full comprehension at 300 wpm, even auctioneers can only speak at about 250 wpm.
953838
1 second = 1 000 000 microseconds
506291
For the slower machine, it would take 3 times the length of time, 8*3=24min\n\nFor the faster machine, it would take 1.5 times, 8*1.5=12min
28176
Without really going into formulae and calculations one can say that the answer for the first question is - a little less than one minute. For the second question - a little less than 60miles an hour.
794482
just multiply by sixty so,\n1.11 x 60 = 66.6 seconds\n:)
887499
avg speed = total distance / total time: \n\ntime 5 min = 1/12 hrs  and \ndistance covered is 140 miles/hr x 1/12 hrs \n= 11 2/3 miles\n\nRemaining distance would take \n[300-11 2/3] / 160 hrs \n=288 1/3 dived ed by 160 \n= 865/480 hrs\n\nTotal time is 1/12 hrs + 865/480 hrs \n= 905/480 hrs giving \n\navg speed as 300 x 480 /905 \n= 159.13 miles/hrs (approx) Ans\nRest of the information is given to 'entertain' the students!
422347
2\n\n60 minutes to a hour\n2x60 = 120
852632
Given: Time 50 minutes ago was  4*50 min after 3 o'clock. T'ime now is 3 o'clock +4*50+50=3 o'clock+250min=\n3 o'clock+250/60=3 o'clock +4hrs and 10min or\n 10 min past 7 o'clock. It's now 1 hr and 10 min after 6 o'clock.
614832
133 msec or around 1/8 of a second.
152036
13,200,000 Milliseconds are in 220 minutes \n\n220 x 60 x 1000
930620
Electronic:  60 words per min = 3600 per hour\nWord processor: 70 words per min = 4200 per hour\n\nElectronic error is 2% so 72 words per hour\nWord processor is 1% so 42 words per hour\n\nThe difference in number of errors made is 72 - 42 = 30 words per hour
996796
20 min.\n\njim goes 1 1/3 miles in 20 min\njohn goes 1 2/3 miles in 20 min\ntogether = 3 miles
696298
1st way :-\ndistance = speed x time = 55 mph x 3 h = 165 m\n\n2nd way :-\ngiven that d = 55t , so on putting t = 3hrs , we get d = 165 m
948100
t-(4/t)=3\ncan be rewritten as\nt^2 - 3t - 4 = 0\n\nthis has 2 possible solutions:\nt=-1\nor\nt=4