Sabrina had a total of 83 pieces of $50 and $10 notes at first. She spent ⁴₇ of the number of $50 notes and received another 7 pieces of $10 notes from her mother. After that, the number of $10 notes she had was ¹₂ of the remaining notes. How much money did Sabrina have at first?

	$50	$10	Total
Before	7 u	3 u - 7	83
Change	- 4 u	+ 7
After	3 u
Comparing $50-notes and $10-notes	1x3 = 3 u	1x3 = 3 u

The number of $50-notes and $10-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 - 7
= 10 u - 7

10 u - 7 = 83
10 u = 83 + 7
10 u = 90

1 u = 90 ÷  10 = 9

Number of $50-notes at first
= 7 u
= 7 x 9
= 63

Total value of $50-notes at first
= 63 x 50
= $3150

Number of $10-notes at first
= 3 u - 7
= 3 x 9 - 7
= 27 - 7
= 20

Total value of $10-notes at first
= 20 x 10
= $200

Amount that Sabrina had at first
= 3150 + 200 
= $3350

Answer(s): $3350