In round $2$ of “Pop the Balloon”, popping each balloon fetched $3$ points. There were $10$ balloons in total. If Benji, Alex, and Susan scored $12,9,$ and $6$ points, respectively, then how many balloons were each one of them not able to pop?

The correct option is B $\text{Benji - 6, Susan - 7, Alex - 8}$
Let’s assume:
Number of balloons popped by Benji $=B$
Number of balloons popped by Susan $=S$
Number of balloons popped by Alex $=A$

According to the question: Points for popping 1 balloon $=3$
Total points scored by Benji $=12$
Total points scored by Alex $=9$
Total points scored by Susan $=6$
Total balloons $=10$

Total points scored $=$ Points for popping $1$ balloon
Number of balloons popped

Total points scored by Benji $=3\times B$
$12=3\times B$
$3\times 4=3\times B$
On comparing, we get $B=4$
Number of balloons Benji was not able to pop $=$ Total balloons - Number of balloons popped $=10-4=6$

Total points scored by Alex $=3\times A$
$9=3\times A$
$3\times 3=3\times A$
On comparing, we get $A=3$
Number of balloons Alex was not able to pop $=$Total balloons - Number of balloons popped $=10-3=7$

Total points scored by Susan $=3\times B$
$6=3\times B$
$3\times 2=3\times B$
On comparing, we get $S=2$
Number of balloons Susan was not able to pop $=$ Total balloons $-$ Number of balloons popped $=10-2=8$

Benji, Alex, and Susan were not able to pop $6,7,$ and $8$ balloons, respectively.