2000 stickers are in 3 packets.
The 2nd packet has 600 stickers more than the total number of stickers in the 1st and 3rd packets.
The 3rd packet has 3 times as many stickers as the 1st packet.
How many stickers does the 2nd packet contain?
Choose the packet with the least stickers to be 1 u.

Number of stickers in the 1st packet = 1 u
Number of stickers in the 3rd packet = 3 u

Number of stickers in the 1st packet and 3rd packet
= 1 u + 3 u
= 4 u

Number of stickers in the 2nd packet = 4 u + 600

Total number of stickers
= 1 u + 3 u + 4 u + 600
= 8 u + 600

8 u + 600 = 2000
8 u = 2000 - 600
8 u = 1400

1 u = 1400 ÷ 8 = 175

Number of stickers in the 2nd packet
= 4 u + 600
= 4 x 175 + 600
= 700 + 600
= 1300

Answer(s): 1300