PSLE The first 15 numbers of a number pattern are given.
6, 4, 9, 8, 6, 4, 9, 8, 6, 4, 9, 8, 6, 4, 9, ...
- What is the 249th number?
- What is the sum of the first 380 numbers?
(a)
Each set of numbers: 6, 4, 9, 8
Each set has 4 numbers.
Remainder: 1 → Number 6
Remainder: 2 → Number 4
Remainder: 3 → Number 9
Remainder: 0 → Number 8
249 ÷ 4 = 62 r 1
249th number = 6
(b)
Sum of each set
= 6 + 4 + 9 + 8
= 27
Number of sets
= 380 ÷ 4
= 95 r 0
Sum of the first 380 numbers
= 95 x 27
= 2565
Answer(s): (a) 6; (b) 2565