There are some red counters and some yellow counters in a bag in the ratio 1 : 5 There are 20 yellow counters in the bag.
Janet puts some more red counters into the bag.
The ratio of the number of red counters to the number of yellow counters is now 1 : 2
How many red counters does Janet put into the bag?

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!)