PSLE Letters A, D and L formed a patten as shown below.
A D A L A A D A L A A D A L A . . .
If there are 52 'A', what is the greatest possible number of letters in the pattern?
Number of letters in 1 set of A D A L A = 5
Number of letters 'A' in 1 set of A D A L A = 3
Number of sets of 3 'A' if there are 52 'A'
= 52 ÷ 3
= 17 r 1
If the remainder is 1, there is 1 'A' and the largest possible number of letters is the final incomplete set is 2. (A D)
If the remainder is 2, there are 2 'A' and the largest possible number of letters is the final incomplete set is 4. (A D A L)
Greatest possible number of letters
= 17 x 5 + 2
= 85 + 2
= 87
Answer(s): 87