Sabrina and Cody collect beads and erasers. Cody has 35 more erasers than beads. Cody has 2 times the number of beads Sabrina has, and Sabrina has 40% more erasers than Cody. After Sabrina gives Cody all of her beads and Cody gives Sabrina 60% of his erasers, Cody has 30 more beads than erasers. Find the number of erasers Sabrina has at first.

Sabrina		Cody
Erasers	Beads	Erasers	Beads
2.8 u + 49	1 u	2 u + 35	2 u
+ 1.2 u + 21	- 1 u	- 1.2 u - 21	+ 1 u
4 u + 70	0	0.8 u + 14	3 u

100% + 40% = 140% 

140% x 2 u
= ¹⁴⁰₁₀₀ x 2 u
= 2.8 u

140% x 35
= ¹⁴⁰₁₀₀ x 35
= 49 

60% x 2 u
= ⁶⁰₁₀₀ x 2 u
= 1.2 u  

60% x 35 
= ⁶⁰₁₀₀ x 35
= 21 

If another 30 erasers are given to Cody, he will have equal number of erasers and beads in the end.
3 u = 0.8 u + 14 + 30
3 u - 0.8 u = 44
2.2 u = 44

1 u = 44 ÷ 2.2 = 20

Number of erasers that Sabrina has at first
= 2.8 u + 49
= 2.8 x 20 + 49
= 56 + 49
= 105
 
Answer(s): 105