<p>can someone explain how to do this problem please?</p>
<p>Every car at a certain dealership is either a convertible, a sedan, or both. if one-fifth of the convertibles are also sedans and one-third of the sedans are also convertibles, which of the following could be the total number of cars at the dealership?</p>
<p>and also, can someone give me tips on solving sequences?</p>
<p>Thanks in advance</p>
<p>If C = #pure convertibles (i.e. not also sedans), S = #pure sedans and B= # that are both convertibles + sedans, then</p>
<p>total #convertibles = C+B and total #sedans = S+B</p>
<p>B = 0.2 (C + B) from which C = 4B
and B = (1/3)(S + B) from which S = 2B</p>
<p>Total #cars = C + S + B = 4B + 2B + B = 7B . So the total#cars is a multiple of 7 ; pick such a number from the possible answers.</p>
<p>If you want to think of it logically without formulas, think of it this way: you've got convertibles, sedans and mixes. From the problem we know 1 out of 5 sedans are mixes (i.e. 4 pure sedans for every mixed car, in ratio of 4:1), and 1 out of 3 convertibles are mixes (i.e. 2 pure convertibles for every mixed car). So for every 1 mixed car, you've got 4 sedans and 2 convertibles. 1 + 2 + 4 = 7. So the answers got to be a multiple of 7.</p>
<p>Might help to draw a venn diagram, though it's more important to have an understanding of ratio and proportions and the difference between them to answer this problem.</p>
<p>wow! thank you optimizerdad and schitz!
both are totally easy to understand</p>
<p>any tips on sequences? like.. how to find xth term in a sequence</p>
<p>Find the pattern and break it (usually after the 5th or so number you plug in you will find the pattern). This is used for when they say. </p>
<p>What is the one's digit of the 3433 term. Just find the pattern for this and you are done.</p>