GMAT Practice Questions -3

1. If $a+5a$ is 6 less than $b+5b$, then $a-b=$
   
   
   1. $6$
   2. $-1$
   3. $-\frac{1}{6}$
   4. $\frac{1}{6}$
   5. $-6$
   
   
2. If $w \ne 0$, $w=5x=\sqrt{5}y$, what is the value of $w-x$ in terms of $y$?
   
   
   1. $5y$
   2. $\frac{\sqrt{5}}{5}y$
   3. $\sqrt{5y}$
   4. $\frac{5}{4\sqrt{5}}y$
   5. $\frac{4\sqrt{5}}{5}y $
   
   
3. If $(a-1)(a+5)(a-7)=0$, and $a < 0$, then $a=$
   
   
   
   1. $-1$
   
   
   2. $-7$
   
   
   3. $-5$
   
   
   4. $-3$
   
   
   5. $-2$
   
   
4. A aytem of equations is as shown below
   $x-l=8$
   $x+m=7 $
   $x-p=6 $
   $x+q=5 $
   What is the value of $l+m+p+q$?
   
   
   1. $-4$
   2. $-3$
   3. $-2$
   4. $-1$
   5. $0$
   
   
5. If $\frac{a^{2}-25}{20a}=\frac{a-5}{a+5}$, $a=5 \ne 0$, and $a \ne 0$, then $a=$
   
   
   1. $1$
   2. $3 $
   3. $5 $
   4. $20 $
   5. $25 $
   
   
6. If $a$, $b$, $c$,and $d$ are not equal to 0 or 1, and if $a^{x}=b$, $b^{y}=c$, $c^{z}=d$ and $d^{t}=a$, then $xyzt=$
   
   
   1. $0$
   2. $ 1$
   3. $ abc$
   4. $abcd $
   5. $a^{b^{c^{d}}} $
   
   
7. If $(x-3y)(x+3y)=-9$ and $(3x-y)(3x+y)=-1$, then $\frac{x^{2}+y^{2}}{x^{2}-y^{2}}=$
   
   
   1. $-2$
   2. $-1 $
   3. $0 $
   4. $1 $
   5. $2 $
   
   
8. If $p-q=5$ and $pq=11$, then is the value of $\frac{1}{p^{2}}+\frac{1}{q^{2}}$?
   
   
   1. $\frac{25}{121}$
   2. $-\frac{47}{121} $
   3. $\frac{5}{11}$
   4. $-\frac{5}{11}$
   5. $\frac{47}{121}$