I’m thinking re the latest vid of @mindyourdecisions

No need to view his vid. Here’s the problem –

Brian has some boxes of paper clips. Some boxes hold 10 clips and some boxes hold 100. He has some paper clips left over. He has 3 more boxes with 100 paper clips than he has boxes with 10 paper clips. He has 2 fewer paper clips left over than he has numbers of boxes with 100 paper clips. What number of paper clips could he have?

  • let x1 be the number of boxes with 10 clips
  • x2 be the number of boxes with 100 clips
  • n be the number of leftover clips

I thought of 100x2 = 10x1 + 300

Is that equation right? Something tells me I shouldn’t equate 100x2 to 10x1 plus 300. Something tells me I shouldn’t make an equation re number of clips as it isn’t explicit in the problem. I’m confused.

  • wuphysics87
    1·
    2 months ago

    You are getting close. You are getting so many answers because you introduced the variable n. This makes it 2 equations and 3 unknowns. You need to cast the 2nd equation in terms of the number of boxes and the number of paper clips in each box rather than an additional variable. Here’s a hint. If:

    x1 * 100 = 300 then x1=3

    I.e. the total number of paperclips from the 100 paperclip boxes is 300 if there are 3 boxes of them