If Bob gave 2/5 of his pennies to Beverly and Beverly gave 2/5 of the pennies she received to Susan then Susan gave 2/5 of the pennies she received to Donald. (Donald received 64 pennies) How many pennies did Bob initially have?

Question

pfenn1 · Answer

Let x = pennies Bob initially had. How many pennies did Bob give to Beverly?

pfenn1 · Answer

*Let x = number of pennies Bob initially had

anonymous · Answer

what would be the equation I would use ?

pfenn1 · Answer

Bob gave 2/5 of his pennies to Beverly therefore Beverly got (2/5)x pennies where x = number of pennies Bob initially had. Now Beverly gave 2/5 of the number of pennies she had to Susan therefor Susan got (2/5)(2/5)x pennies.  Right?

anonymous · Answer

yes

anonymous · Answer

and donald recieved 64 pennies which was  2/5^3 of the original pennies

pfenn1 · Answer

Right!

anonymous · Answer

I know this but how wold I come to the result?
What equation would I use?

pfenn1 · Answer

The number of pennies Donald received is (2/5)^3 of the original pennies Bob started with.  Can you write an equation that expresses that idea?

anonymous · Answer

tried but no success which is why I posted here to find an equation that would work

anonymous · Answer

so can you give me an equation?

pfenn1 · Answer

number of pennies Donald received = 64
x= number of pennies Bob started with
so the equation is$$64=\left( \frac 25 \right)^3x$$

pfenn1 · Answer

Rearrange and solve for x.

lgbasallote · Answer

wouldnt it be neater to simplify it already?$$\large 64 = \frac{8x}{125}$$

anonymous · Answer

@crzymom2u are you following?

anonymous · Answer

got the answer is 1000

pfenn1 · Answer

Yes!