46. Tia adds three consecutive prime numbers

5 + 7 + 11 = 23

She does this two more times

7 + 11 + 13 = 31

11 + 13 + 17 = 41

Tia is delighted to see that the sum of three consecutive prime numbers seems to give

another prime number.

(a) Complete the following statements:

(i) 17 + 19 + 23 =

(ii) + + = 71

(iii) + + = 83

The prime numbers between 20 and 140 are:

23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109,

113, 119, 127, 131, 137 and 139

(b) Which two groups of three consecutive prime numbers, between 10 and 50, have

a sum which is not prime?

Answer: + + =

+ + =