Mrs Oh had a sum of money. She gave her daughter $134 and gave ¹₆ of the remaining money to her niece. She used ⁷₈ of the rest of the money on a refrigerator and was left with ¹₁₀ of the amount she had at first. What was the sum of money she had at first?

Her daughter	Her niece	Remaining amount		Total
$134	1x8	5x8
		Refrigerator	Left
		7x5	1x5
9x5 = 45 u			1x5 = 5 u
2 u	8 u	35 u	5 u	50 u

Fraction of the remaining amount left 
= 1 - ⁷₈
= ¹₈

The remaining amount is repeated.  Make the remaining amount the same. LCM of 5 and 8 is 40. 

The amount left is repeated.  Make the amount left the same.

¹₈ Remaining amount = ¹₁₀ Total amount

Amount that Mrs Oh gave to her daughter
= 45 u - 8 u - 35 u
= 2 u

2 u = 134

1 u = 134 ÷ 2 = 67

Total amount that Mrs Oh had at first
= 2 u + 8 u + 35 u + 5 u
= 50 u
= 50 x 67
= $3350

Answer(s): $3350