Let $t$ be TNYWR.

The numbers $a$ and $b$ satisfy both of the following equations.

$$
\begin{aligned}
& a-\frac{t}{6} b=20 \\
& a-\frac{t}{5} b=-10
\end{aligned}
$$

What is the value of $b$ ?

##
Subtracting the second equation from the first gives

$$
\left(a-\frac{t}{6} b\right)-\left(a-\frac{t}{5} b\right)=20-(-10)
$$

which simplifies to $\left(\frac{t}{5}-\frac{t}{6}\right) b=30$ or $\frac{t}{30} b=30$.

Solving for $b$ gives $b=\frac{900}{t}$. Substituting $t=60$ gives $b=\frac{900}{60}=15$.