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Last updated at June 13, 2018 by Teachoo

Transcript

Ex 3.2, 11 Write five pairs of prime numbers less than 20 whose sum is divisible by 5. (Hint : 3 + 7 = 10)Numbers divisible by 5 are 5, 10, 15, 20, 25, 30 (All these are also called multiples of 5) We need to write these as sum of 2 prime numbers less than 20 i.e. using 2, 3, 5, 7, 11, 13, 17, 19 (1) 5 = 2 + 3 (2) 10 = 3 + 7 (3) 15 = 2 + 13 (4) 20 = 3 + 17 (5) 20 = 7 + 13 So Pairs are (2, 3) ; (3, 7) ; (2, 13) ; (3, 17) ; (7, 13) (Both 2 and 3 are prime) (Both 3 and 7 are prime) (Both 2 and 13 are prime) (Both 3 and 17 are prime)

Ex 3.2

Ex 3.2, 1

Ex 3.2, 2 (a) Important

Ex 3.2, 2 (b)

Ex 3.2, 2 (c)

Ex 3.2, 2 (d)

Ex 3.2, 2 (e)

Ex 3.2, 2 (f)

Ex 3.2, 2 (g)

Ex 3.2, 2 (h)

Ex 3.2, 2 (i)

Ex 3.2, 3

Ex 3.2, 4

Ex 3.2, 5

Ex 3.2, 6 (a)

Ex 3.2, 6 (b)

Ex 3.2, 6 (c)

Ex 3.2, 6 (d)

Ex 3.2, 7

Ex 3.2, 8 Important

Ex 3.2, 9

Ex 3.2, 10 Important

Ex 3.2, 11 You are here

Ex 3.2, 12 Important

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.