Janice bought 30 items each priced at 30 cents, 2 dollars or 3 dollars. If her total purchase price was $30.00, how many 30-cent items did she purchase?
we know that 10 3-dollars will worth 30 dollars, so items that cost 3 dollars have to be less than ten.
We also know that 10 30-cents will worth 3 dollars, so the number of cents has to come in 10s since the final cost is 30 which is a whole number.
There will be a lot of cents, so I will just say that there are 20 30-cents, which will cost 6 dollars. If I add 6 2-dollars, then I will get 12 dollars. 12 +6=18. 30-18=12. and 12/3=4.
4 items cost $3
6 items cost $2
20 items cost 30 cents