Answer:
4 months
Step-by-step explanation:
The first planet we know grow 3 inches per month and starts at 6 inches. While the second plant is 2 inches and grows 4 inches per month, as 50-2 (the start of the inches) = 48. 48/12 months = 4 inches per month.
With this information we can slowly add up the time.
1st Month
Planet 1: 9 inches
Planet 2: 6 inches
2nd Month
Planet 1: 12 inches
Planet 2: 10 inches
3rd Month
Planet 1: 15 inches
Planet 2: 14 inches
4th Month
Planet 1: 18 inches
Planet 2: 18 inches
