Ivan and Michael have some pink notebooks and some purple notebooks. The number of purple notebooks Ivan has is equal to the number of pink notebooks Michael has. ¹₅ of Ivan's notebooks are pink and ¹₄ of Michael's notebooks are purple. There are a total of 30 pink notebooks. Find the total number of notebooks they have.

Ivan		Michael		Total
Pink	Purple	Pink	Purple
	1x12	1x12
1x3	4x3	3x4	1x4
3 u	12 u	12 u	4 u	31 u

The number of Ivan's purple notebooks and Michael's pink notebooks is the same.

The number of Ivan's purple notebooks is repeated. The number of Michael's pink notebooks is repeated.  Make the number of Ivan's purple notebooks and Michael's pink notebooks the same.  LCM of 4 and 5 is 12.

Number of pink notebooks
= 3 u + 12 u
= 15 u

15 u = 30

1 u = 30 ÷ 15 = 2

Total number of notebooks
= 3 u + 12 u + 12 u + 4 u
= 31 u
= 31 x 2
= 62

Answer(s): 62