Erika, Zoe and Anna have equal number of stickers. Erika packs all her stickers equally into 10 packets. Zoe packs all her stickers equally into 6 packets. Anna packs all her stickers equally into 5 packets. 5 packets of Erika's stickers, 4 packets of Zoe's stickers and 3 packets of Anna's stickers add up to 530 stickers. How many stickers do they have altogether?

	Erika	Zoe	Anna
Number of packets	10	6	5
Number of stickers	30 u	30 u	30 u
Number of stickers in each packet	3 u	5 u	6 u

All the stickers can be put into the packets without remainder.

All the children have equal numbers of stickers. 
Make the number of stickers that each child has the same. LCM of 10, 6 and 5 = 30

Number of stickers that each child has = 30 u

Number of stickers in 1 packet of Erika's stickers = 30 u ÷ 10 = 3 u
Number of stickers in 1 packet of Zoe's stickers = 30 u ÷ 6 = 5 u
Number of stickers in 1 packet of Anna's stickers = 30 u ÷ 5 = 6 u

Number of stickers in 5 packets of Erika's stickers, 4 packets of Zoe's stickers and 3 packets of Anna's stickers
= (5 x 3 u) + (4 x 5 u) + (3 x 6 u)
= 15 u + 20 u + 18 u
= 53 u

53 u = 530

1 u = 530 ÷ 53 = 10

Total number of stickers that they have
= 3 x 30 u
= 90 u
= 90 x 10
= 900

Answer(s): 900