### Instruction: Every 5 months, Hal has to replace the batteries in his calculator. He changed them the first time in May. In what month will they be changed the 25th time?### Response: To find the month when the batteries are changed the 25th time, I need to figure out how many months have passed since the first time.
If Hal changes the batteries every 5 months, then the number of months that have passed is a multiple of 5.
I can write this as 5n, where n is the number of times he has changed the batteries, not counting the first time.
So, when he changes them the 25th time, n will be 24, since I don't count the first time.
That means 5n will be 5 times 24, which is 120.
So, 120 months have passed since the first time he changed the batteries in May.
To find the month that is 120 months after May, I can divide 120 by 12, since there are 12 months in a year.
This gives me 10, which means that 10 years have passed.
So, the month will be the same as the starting month, which is May.