The number of mangosteens Henry bought in September was 30% more than in August. In October, he bought 60% less mangosteens than in September. If there were 264 less mangosteens in October than August, how many mangosteens did Henry buy in September?

August	September	October
10x5	13x5
	5x13	2x13
50 u	65 u	26 u

100% + 30 = 130%
130% = ¹³⁰₁₀₀ = ¹³₁₀
September : August = 13 : 10 

100% - 60% = 40%
40% = ⁴⁰₁₀₀ = ²₅
October : September = 2 : 5

The number of mangosteens in September is repeated.  Make the number of mangosteens in September is the same.  LCM of 13 and 5 is 65.

Number of less mangosteens in October than August
= 50 u - 26 u
= 24 u

24 u = 264

1 u = 264 ÷ 24 = 11

Number of mangosteens that Henry bought in September
= 65 u
= 65 x 11
= 715

Answer(s): 715