Answer
Answer B
Work Step by Step
Let x = time working together
One writes 7 names in 6 minutes: $\frac{7}{6}x$
Another writes 17 names in 10 minutes $\frac{17}{10}x$
The third writes 23 names in 15 minutes: $\frac{23}{15}x$
If they work together: $\frac{7}{6}x+\frac{17}{10}x+\frac{23}{15}x=440$
$\frac{35x+51x+46x}{30}=440$
$35x+51x+46x=13200$
$132x=13200$
$x=100$
The correct answer is B.
