Note: If you buy 6 trees in 20 yuan, you will get 1 tree, which is equivalent to buying 7 seedlings in 120 yuan. If you want 350 trees, it is 350÷7=50. If you want 50 trees, it is 120 yuan, which means 50× 120=6000 yuan.

20×6= 120 (yuan)

350÷(6+ 1)=50

50× 120=6000 (yuan)