Betty has 30% as many cards as Hazel. Hazel has 140% as many cards as Anna. If Hazel gives 80 cards to Anna, both will then have an equal number of cards. Find the average number of cards the three of them have.

Betty	Hazel	Anna
3x7	10x7
	7x10	5x10
21 u	70 u	50 u

30% = ³⁰₁₀₀ = ³₁₀
140% = ¹⁴⁰₁₀₀= ⁷₅

The number of cards that Betty has is repeated.  Make the number of cards that Betty has the same. LCM of 10 and 7 is 70.

	Hazel	Anna	Total
Before	70 u	50 u	120 u
Change	- 10 u	+ 10 u
After	60 u	60 u	120 u

Total number of cards that Hazel and Anna have
= 70 u + 50 u
= 120 u

After Hazel gives to Anna, both of them will have the same number of cards. 

The total number of cards that Hazel and Anna have remains unchanged.

Number of cards that each of them will have
= 120 u ÷ 2
= 60 u

Number of cards that Hazel gives to Anna
= 70 u - 60 u
= 10 u

10 u = 80

1 u = 80 ÷ 10 = 8

Total number of cards that three of them have
= 120 u + 21 u
= 141 u

Average number of cards that each of them have
= 141 u ÷ 3
= 47 u
= 47 x 8
= 376

Answer(s): 376