Gabby had a total of 108 pieces of $50 and $5 notes at first. She spent ⁴₇ of the number of $50 notes and received another 12 pieces of $5 notes from her mother. After that, the number of $5 notes she had was ¹₂ of the remaining notes. How much money did Gabby have at first?

	$50	$5	Total
Before	7 u	3 u - 12	108
Change	- 4 u	+ 12
After	3 u
Comparing $50-notes and $5-notes	1x3 = 3 u	1x3 = 3 u

The number of $50-notes and $5-notes in the end is the same.

The number of $50-notes in the end is repeated.  Make the number of $50-notes in the end the same. LCM of 1 and 3 is 3.

Number of notes at first
= 7 u + 3 u - 12
= 10 u - 12

10 u - 12 = 108
10 u = 108 + 12
10 u = 120

1 u = 120 ÷  10 = 12

Number of $50-notes at first
= 7 u
= 7 x 12
= 84

Total value of $50-notes at first
= 84 x 50
= $4200

Number of $5-notes at first
= 3 u - 12
= 3 x 12 - 12
= 36 - 12
= 24

Total value of $5-notes at first
= 24 x 5
= $120

Amount that Gabby had at first
= 4200 + 120 
= $4320

Answer(s): $4320