Batteries come in packs of 4. Last month, Joe used 58 batteries in his remote control drone. How many packs of batteries did he have to open?

It is given that batteries come in a packs of 4. It means in each pack there are 4 batteries.

Joe used 58 batteries. So to find the total number of packets of batteries joe has to open is

Number of batteries used / Total number of batteries in each packet

= 58 / 4

= 14.5

The number of battery can not be in decimal. So we will round the answer to integer. If we round it to 14 it means 14 packets. But in 14 packets there are 14*4 = 56 batteries.

But we know that Joe used 58 batteries. So we will round the final answer to 15.

It means Joe has to open 15 packets of batteries.