Mathematics - Class ...

Q1.

What are prime numbers?

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Q2.

What are composite numbers?

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Q3.

Write all the prime numbers from 1 to 50.

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Q4.

Write the prime number between 60 and 90.

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Q5.

Circle the prime numbers.

41, 42, 43, 44, 45, 46, 47, 48, 49, 50

Q6.

Can there be any natural number that does not have factor at all?

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Q7.

Write down 7 consecutive numbers which are not prime numbers.

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Q8.

Express 31 as the sum of 3 odd prime numbers.

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Q1.

What are co-prime numbers? Give example.

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Q2.

Are all co-prime numbers are prime?

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Q3.

True/False.

a.  The smallest composite number is 4. _________

b.  The smallest prime number is 1. ____________

c.  1 is neither prime nor composite.__________

d.   A prime number is a number that has only two factors i.e. 1 and itself. __________

e.   A number which has more than three factors is called a composite number. ____________

f.    All prime numbers are odd numbers. __________

g.   1 is co-prime with every number. ___________

h.   Every prime number is not a co-prime to each other. __________

i.     Any two successive numbers are always co-primed. __________

j.    The sum of two prime numbers is always a prime number. _______

k.   The H.C.F of two prime numbers is always 1. ________

Q4.

Write two pair of prime numbers whose difference is 1.

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Fill in the blanks.

a.   _______________ is the even prime number.

b.   _______________ is the first composite number.

c.   The smallest odd prime number is _____________.

d.   ______________ is the neither prime nor composite number.

e.   The sum two prime numbers can be even or__________.

f.    14 and 15 is a pair of __________________ number.

g.   H.C.F of two prime numbers is always _________.

h.   ____________ are the prime numbers greater than 30 and less than 40.

i.     73 is a ____________ number.

j.    96 is a ____________ number.

k.   Prime numbers are natural numbers that have only 2 factors i.e. 1 and_____________.

l.     The two numbers are said to be co-prime numbers when there is no number, other than_______, that divides both the two given number evenly.

m. A ____________ number has factors in addition to one and itself.

n.   Every prime number except 2 is_______________.

o.   If any whole number greater than 1 is not a prime number, then it is a _____________ number.

p.   10, 12 and 18 are _______________ numbers.