<p>In the table above, each of the six empty boxes should contain a number entry so that the column and row totals are as given. Juan wants to complete the table. What is the least number of entiries that he must ask for in order to complete the table?</p>
<p>A 1
B 2
C 3
D 4
E 6</p>
<hr>
<p>I put C, but the book says it is B. I could see how if you are given like Row1/Column1 and Row2/Column1 you could get all the answers but what if you were given Row1/Column1 and Row1/Column2, how could you get the rest then?</p>
<p>Thanks for your help again!!!</p>
<p>(ps: I am going to try to make it through most of the 10 Real SATs by next Saturdays test. 3 down, 7 to go...)</p>
<p>Two cities n miles apart are located s inches apart on a certain map that is drawn to scale. What is the distance, in inches, on the map between two cities that are n + 1 miles apart?</p>
<p>A n/s
B (n+1)/s
C s/(n+1)
D s(n+1)/n
E n/s(n+1)</p>
<p>not sure about the first one (i can remember that I got it incorrect as well and did not understand it), but for the second one simply set up a proportion...</p>
<p>"n is to s as n+1 is to x"
n/s=(n+1)/x and solve for x
x=s(n+1)/n</p>
<p>Yeah, I seem to remember the first question being a controversy on this board. It's all in the wording. That question is from 10 Reals right? It should be worded, "what is the least possible he needs to have?" I agree with you.</p>
<p>Actually, it is always possible to complete the table if you're given at the very least two entires. Suppose you're given the entries of (1,1) and (1,2). Then you will have four unknowns, which are the values of (2,1); (2,2); (3,1); (3,2). But then again, from the given information we also know that (2,1) + (2,2) = 26, (3,1) + (3,2) = 21, (2,1) + (3,1) = 36 - (1,1), and (2,2) + (3,2) = 64 - (1,2). 4 unknown, 4 equations. Has it rung any bell yet?</p>
<p>Two cities n miles apart are located s inches apart on a certain map that is drawn to scale. What is the distance, in inches, on the map between two cities that are n + 1 miles apart?</p>
<p>A n/s
B (n+1)/s
C s/(n+1)
D s(n+1)/n
E n/s(n+1)</p>
<p>For this type of problem i generally use numbers for example if n=50 and you make s=10 then the corresponding inches for n+1=51 would be 10.2. Only D gives you 10.2 when you plug it in. </p>
<p>For the first problem, again plug in the table for one value, 2 values and see that when you have two values then the table is complete</p>
<p>You got 4 unknowns and 4 equations, which means that you can solve for all of the unknowns. It doesn't matter which of the entries that you're given, you will always have 4 unknowns and 4 equations, which is why the least number of entries that he must ask in order to complete the table is two.</p>
<p>EDIT: nevermind! If that's really the case, then knowing just one of the entries will be sufficient to solve the problem. Also, with just two entries from the same row, as I try putting in numbers, you can still get more than one more possible ways to complete the table. My bad.</p>