Question 598290
Hi, there--
.
Let
D = a dime on the table
Q = a quarter on the table
N = nickel on the table
P = a penny on the table.

18 dimes in a row:
.
D D D D D D D D D D D D D D D D D D
.
Simone exchanges each third coin for a quarter; 
.
D D Q D D Q D D Q D D Q D D Q D D Q
.
then she exchanges each second coin for a nickel;
.
D N Q N D N D N Q N D N D N Q N D N
.
finally, she exchanges each ninth coin for a penny.
.
D N Q N D N D N P N D N D N Q N D P
.
.
After Simone's switches, there are 
6 dimes: 6*10 = 60 cents
8 nickels: 8*5 = 40 cents
2 quarters: 2*25 = 50 cents
2 pennies: 2*1 = 2 cents
.
The total amount of money is 152 cents.
.
Feel free to email via gmail if the solution is unclear.
.
Ms.Figgy
math.in.the.vortex@gmail.com