Answer:
8 $10 notes
Step-by-step explanation:
I started by working it backwards. $93-$3 equals $90. So we have three of our 13 notes. We need ten more. Well the most $10 notes we can have is 8. if we had 8 $10 notes that would give us $80. $90-$80=10. We can take ten and divide it by five so we have 2 $5 notes.
So in total he would have 8 $10 notes, 2 $5 notes, and $3 one dollar notes which adds up to 13 notes
Y=5/2 should be the answer
For an investment compounded continuously, the rule of 69 gives a better approximation than the rule of 72 (for normal compound interests).
