Buy two bags, each at 100 yuan;

Buy two bags, one for 50 yuan and one for 150 yuan;

Buy three bags, two bags of 50 yuan, one bag 100 yuan.

(2)(50+ 100+ 150)X2

=300X2

=600

A: If you buy two bags of each kind of sugar, 500 yuan will be enough.

4. Left: 220+290=5 10

Right:196+385+210 = 791.