Kathy made 187 more pandan cookies than cream cookies. After she gave away ³₇ of the pandan cookies and ¹₈ of the cream cookies, there were an equal number of pandan cookies and cream cookies left. How many pandan cookies did she give away?

	Pandan cookies	Cream cookies	Difference
Before	7x7 = 49 u	8x4 = 32 u	17 u
Change	- 3x7 = - 21 u	- 1x4 = - 4 u
After	4x7 = 28 u	7x4 = 28 u

Fraction of pandan cookies left
= 1 - ³₇
= ⁴₇

Fraction of cream cookies left
= 1 - ¹₈
= ⁷₈

The number of pandan cookies and cream cookies in the end is the same. Make the numerators the same.  LCM of 7 and 4 is 28.

⁴₇ of pandan cookies = ⁷₈ of cream cookies
²⁸₄₉ of pandan cookies = ²⁸₃₂ of cream cookies

Number of more pandan cookies than cream cookies at first
= 49 u - 32 u
= 17 u

17 u = 187

1 u = 187 ÷ 17 = 11

Number of pandan cookies that Kathy gave away
= 49 u - 28 u
= 21 u
= 21 x 11
= 231

Answer(s): 231