7^6 is the correct answer
First find out how many more inches it needs to grow, 54-37.5; It needs to grow 16.5 more inches. If it grows 3 inches a year then you have to do 16.5/3; 5.5. It will take 5.5 or 5 1/2 more years to grow to 54 inches.
I'm not entirely sure but it should be (3/5) together. For pen the probability is (5/20) and for crayon is (12/20) add them equals (12/20) simply equals (3/5) HOPE IT HELPS
800/5 which is 160!!!!!!!!