Red bag 20 percent greater than blue bag. Red bag costs 50 percent more than blue bag. For same mass red bag costs how much more than blue in percent

Question

For same mass, red bag costs more than blue bag by what percent

Answer 1

Imagine the blue bag to be 100 units big and cost $100, so 1 unit costs $1.

The red bag must be 120 units big, and costs $150, so 1 unit costs 150/120=5/4=$1.25. The red bag units cost 25c more than the blue bag, which is 25% of $1. That means for the same mass (1 unit) the red bag costs 25% more than the blue bag.