Mrs Choo gave Barbara and Diana some money each on Wednesday. On Thursday, Barbara gave ¹₆ of the amount she had to Diana. On Friday, Diana gave ¹₅ of the amount she had to Barbara. In the end, Barbara had $54 and Diana had $16. How much did Diana had more than Barbara at first?

	Barbara	Diana	Total
Before 1	6 u	?	$70
Change 1	- 1 u	+ 1 u
After 1	5 u	5 p	$70
Before 2	$54 - 1 p	5 p	$70
Change 2	+ 1 p	- 1 p
After 2	$54	4 p ($16)	$70

Amount that Diana had in the end = 4 p

4 p = 16

1 p = 16 ÷ 4 = 4

Working backwards.

Amount that Barbara had after giving to Diana on Thursday
= 54 - 1 p
= 54 - 4
= $50

5 u = 50

1 u = 50 ÷ 5 = 10

Amount that Barbara had at first
= 6 u
= 6 x 10
= $60

Total amount that Barbara and Diana had 
= 54 + 16
= $70

Amount that Diana had at first
= 70 - 60
= $10

Amount that Barbara had more than Diana
= 60 - 10 
= $50

Answer(s): $50