math question

Test Preparation
1

<p>10 Real SAT 3rd edition. page 340 (it's the 2nd test), question 22:</p>

<pre><code> AB
</code></pre>

<p>+BA</p>

<hr>

<p>CD4</p>

<p>In the addition problem above, each letter represents a different nonzero digit. What is one possible value of the 2 digit number AB??</p>

<p>I understand why the answer is 68 or 86 (that's the correct answer). but i DO NOT UNDERSTAND why AB cannot be either 95 or 59 because 95+ 59 also equals a 3 digit number that ends with a 4.</p>

<p>2nd question: Same book, page 349 (2nd test), question 10.
The points P and T line on line L in the figure above (I can't draw the figure). How many points on line L are twice as far from point T as from point P? </p>

<p>I do not understand what the question wants.</p>

2

<p>each letter represents a DIFFERENT, non zero digit.
If you used 59 or 95 for AB,
59 + 95 = 154, meaning that D = A or B (depending on which one is 59 and which one is 95). Since D equals either A or B, those are clearly not different, so that is why it cannot be 59 or 95.</p>