PSLE
At first, Emily had an equal number of black and yellow marbles . She gave away ²₅ of her black marbles and some yellow marbles. In the end, she was left with ²₃ of her marbles. What fraction of the yellow marbles did Emily give away?

	Black	Yellow	Total
Comparing black marbles and yellow marbles at first	1x5x3 = 15 u	1x5x3 =  15 u	2x5x3 =  30 u
Before	5x3 = 15 u	15 u	3x10 = 30 u
Change	- 2x3 = - 6 u	- 4 u	- 2x10 = - 10 u
After	3x3 = 9 u	11 u	1x10 = 20 u

After3_x3 =
9 u
11 u1_x10 =
20 u
The number of black marbles at first is repeated. Make the number of black marbles the first the same. LCM of 5 and 1 is 5.

The total number of marbles at first is repeated. Make the total number of marbles at first the same. LCM of 10 and 3 is 30.

Number of yellow marbles that Emily was left with
= 20 u - 9 u
= 11 u

Number of yellow marbles that Emily gave away
= 15 u - 11 u
= 4 u

Fraction of the yellow marbles that Emily gave away = ⁴₁₅

Answer(s): ⁴₁₅