So I’m doing this word problem with Sam. I have the answer but I don’t
know WHY it is the answer. Can any of you out there in cyberspace
help?
Here is the question:
Sarim has $1 in coins. One-fifth of the coins are dimes,
two-fifteenths are nickels, and two-thirds are pennies. Tell how many
of each coin he has.
The answer:
6 dimes; 4 nickels; 20 pennies; making 30 coins
Now that makes sense because all the fractions work into the total
number of coins nicely. (i.e. 1/5 of 30 is 6… pennies) But how would
I have attacked this problem and more importantly (to me) why would I
do it that way…
Anyone?
Posted via email from The Sinister Scribe
Wouldn’t you just make them all have a common denominator? 6/30 + 4/30 + 20/30 = 30
That is how I would have it.
Barb
My brain works through that by figuring out the lowest common denominator, and the totals of the coins for each that way, and then going up from there to get the desired total. (Okay…we have 15ths and 5ths and 3rds, so a LCD of 15 would work…which would mean thirty cents in dimes, ten cents in nickels, and ten cents in pennies…but that’s only fifty cents total, which is half what we need, so multiplying each coin total by two would give us the total we need.)
At least, that’s how MY brain works.