Mrs Lee had a sum of money. She gave her father $2304 and gave ¹₆ of the remaining money to her mother. She used ³₄ of the rest of the money on a laptop and was left with ¹₈ of the amount she had at first. What was the sum of money she had at first?

Her father	Her mother	Remaining amount		Total
$2304	1x4	5x4
		Laptop	Left
		3x5	1x5
7x5 = 35 u			1x5 = 5 u
16 u	4 u	15 u	5 u	40 u

Fraction of the remaining amount left 
= 1 - ³₄
= ¹₄

The remaining amount is repeated.  Make the remaining amount the same. LCM of 5 and 4 is 20. 

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

¹₄ Remaining amount = ¹₈ Total amount

Amount that Mrs Lee gave to her father
= 35 u - 4 u - 15 u
= 16 u

16 u = 2304

1 u = 2304 ÷ 16 = 144

Total amount that Mrs Lee had at first
= 16 u + 4 u + 15 u + 5 u
= 40 u
= 40 x 144
= $5760

Answer(s): $5760