PSLE Letters E, C and U formed a patten as shown below.
E C E U E E C E U E E C E U E . . .
If there are 70 'E', what is the greatest possible number of letters in the pattern?
Number of letters in 1 set of E C E U E = 5
Number of letters 'E' in 1 set of E C E U E = 3
Number of sets of 3 'E' if there are 70 'E'
= 70 ÷ 3
= 23 r 1
If the remainder is 1, there is 1 'E' and the largest possible number of letters is the final incomplete set is 2. (E C)
If the remainder is 2, there are 2 'E' and the largest possible number of letters is the final incomplete set is 4. (E C E U)
Greatest possible number of letters
= 23 x 5 + 2
= 115 + 2
= 117
Answer(s): 117