Answer:
Janet put 6 red counters into the bag
Step-by-step explanation:
There are 5 yellow counters for every 1 red counter. If there are 20 yellow counters in the bag then there are 4 red counters. (20/5). If the ratio becomes 1:2 this means there are 2 yellow counters for every 1 red counter. There are 20 yellow counters so there must be 10 red counters in the bag. (20/2). 10 - 4 = 6. Janet put 6 red counters into the bag. (Brainliest would be appreciated!)