Kylie and Ivan collect pencils and marbles. Ivan has 60 more marbles than pencils. Ivan has 4 times the number of pencils Kylie has, and Kylie has 40% more marbles than Ivan. After Kylie gives Ivan all of her pencils and Ivan gives Kylie 70% of his marbles, Ivan has 20 more pencils than marbles. Find the number of marbles Kylie has at first.

Kylie		Ivan
Marbles	Pencils	Marbles	Pencils
5.6 u + 84	1 u	4 u + 60	4 u
+ 2.8 u + 42	- 1 u	- 2.8 u - 42	+ 1 u
8.4 u + 126	0	1.2 u + 18	5 u

100% + 40% = 140% 

140% x 4 u
= ¹⁴⁰₁₀₀ x 4 u
= 5.6 u

140% x 60
= ¹⁴⁰₁₀₀ x 60
= 84 

70% x 4 u
= ⁷⁰₁₀₀ x 4 u
= 2.8 u  

70% x 60 
= ⁷⁰₁₀₀ x 60
= 42 

If another 20 marbles are given to Ivan, he will have equal number of marbles and pencils in the end.
5 u = 1.2 u + 18 + 20
5 u - 1.2 u = 38
3.8 u = 38

1 u = 38 ÷ 3.8 = 10

Number of marbles that Kylie has at first
= 5.6 u + 84
= 5.6 x 10 + 84
= 56 + 84
= 140
 
Answer(s): 140