Answer:
60
Explanation:
Since both bags of sugar were 120 kg, there is a total of 240 kg of sugar to be distributed into the packs. Let x represent the number of 2 kg packets and y represent the number of 3 kg packets. We know that all the sugar was packed into these two kinds of packets, so:

And we know that there were half as many 2 kg packets as 3 kg packets, so:

Now, we have a system of equations!

Let's put the second equation equal to y, since that removes the fraction:

Now substitute y into the first equation:

Now simplify to find x:

There are 30 of the 2 kg packets! Now, we can use x to find y, the number of 3 kg packets!

There are 60 of the 3 kg packets!