Blue Book pg 735 #7

Test Preparation SAT Preparation
1

<p>A certain scale only registers weights that are greater than 6 pounds. A person who wanted to know the weights of a puppy, a kitten, and a bunny weighed them in pairs and got the following results.</p>

<p>The kitten and the bunny weighed 7 pounds.
The kitten and the puppy weighed 8 pounds.
The bunny and the puppy weighed 9 pounds.</p>

<p>What is the weight of the puppy?</p>

<p>(A) 2 pounds
(B) 3 pounds
(C) 4 pounds
(D) 5 pounds
(E) 6 pounds</p>

2

<p>This is given : </p>

<p>k = kitty weight
b = bunny weight
p = puppy weight</p>

<p>k + b = 7</p>

<p>k + p = 8</p>

<p>b + p = 9</p>

<p>Solving is all substitution</p>

<p>p = 9 - b</p>

<p>p = 8 - k</p>

<p>k = 7 - b </p>

<p>Next</p>

<p>9 - b = 8 - k</p>

<p>9 - b = 8 - ( 7 - b)</p>

<p>b = 4 </p>

<p>put it in the equation b + p = 9</p>

<p>and get D</p>