Math Is Fun Forum

Abbey78336

Member

Registered: 2022-08-15

Posts: 37

How many dollars ?

If Two US pennies Weigh as one quater. 4 kg of US pennies make $100 4 kg of US quaters will make ????

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,385

Re: How many dollars ?

Abbey78336,

Is it a puzzle posted or do you need help?

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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

sologuitar

Member

Registered: 2022-09-19

Posts: 467

Re: How many dollars ?

Where exactly are you stuck? Show some effort at your end.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,619

Re: How many dollars ?

hi Abbey78336

You need to find out how much a penny and a quarter weigh.  Do this :

4kg pennies is worth $100

I think it's easier to work in g rather than Kg as you'll end up with 0.000....  rather a lot of zeros otherwise.

Convert the RHS to pennies and the LHS to g

4000g is worth ????? pennies  Convert dollars to pennies.

Hence one penny weighs ????  Divide weight by number of pennies to get the weight of one penny.

Hence one quarter weighs ????

Let x quarters weigh 4Kg = 4000g = [weight of one quarter] times x

Solve for x.

That will give the number of quarters.  If you also want the value you'll have to convert to dollars.

LATER EDIT:

i've thought of another way to do this which is quicker.

Imagine you've got a two scale pan balance.  4Kg weight on one side a $100 in pennies on the other.

It balances.

How many pennies is that?

Quarters are twice as heavy so it'll only need helf as many to balance the 4Kg.

If you post back your working I'll check it for you.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob