Respuesta :
Answer:
1, 3, 5, 7, 9, 11
19
Step-by-step explanation:
Given,
Step 1 : A,
Step 2 : ABA
Step 3 : ABCBA
By proceeding the pattern,
Remaining steps are,
Step 4 : ABCDCBA,
Step 5 : ABCDEDCBA
Step 6 : ABCDEFFEDCBA
Thus, the number of letters in each steps are,
1, 3, 5, 7, 9, 11
Which is an AP having first term, a = 1,
Common difference, d = 3 - 1 = 2,
Hence, the number of letters in step 10 = 10th term of the above AP
= a + (10-1)d
= 1 + 9(2)
= 1 + 18
= 19