<p>I always get these kind of questions wrong.
I really need help</p>
<p>The smith metal company's old machine makes 300 bolts per hour. Its new machine makes 450 bolts per hour. If both machine begin running at the same time, how many minutes will it take the two machines to make a total off 900 bolts?</p>
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<p>Well the old machine can make a total of 5 bolts/min and the new machine can make 7.5 bolt/min. Together they can make a total of 12.5 bolts/min. 900/12.5=72mins. Hope that helps.</p>
<p>i like using dimensional analysis cuz i think its easier to understand what you’re doing</p>
<p>(300bolt/hour) (x hour) + (450 bolt/hour) (x hour)= 900 bolts</p>
<p>solve for x.
convert to minutes.</p>
<p>you know what to multiply cuz u can look at the units. hour/ hour = 1 so it cancels.</p>
<p>I did it the way Linger did it. Took me 15 seconds. I think that’s the best way.</p>
<p>Dimensional analysis… canceling out units… that skill is quite great and comes in handy.</p>
<p>lingers way is the way i use high 5 x)</p>