PSLE The first 15 numbers of a number pattern are given.
6, 7, 3, 9, 6, 7, 3, 9, 6, 7, 3, 9, 6, 7, 3, ...
- What is the 159th number?
- What is the sum of the first 445 numbers?
(a)
Each set of numbers: 6, 7, 3, 9
Each set has 4 numbers.
Remainder: 1 → Number 6
Remainder: 2 → Number 7
Remainder: 3 → Number 3
Remainder: 0 → Number 9
159 ÷ 4 = 39 r 3
159th number = 3
(b)
Sum of each set
= 6 + 7 + 3 + 9
= 25
Number of sets
= 445 ÷ 4
= 111 r 1
First 1 number = 6
Sum of the first 445 numbers
= (111 x 25) + 6
= 2775 + 6
= 2781
Answer(s): (a) 3; (b) 2781