Page 92 - ICSE Math 4

2. Choose the correct op on.
(a) ___________ is a prime number.

(i) 20 (ii) 32 (iii) 37 (iv) 49
(b) ___________ is a factor of every number.

(i) 0 (ii) 1 (iii) 2 (iv) 3
(c) The greatest factor of 128 is ___________.

(i) 4 (ii) 12 (iii) 24 (iv) 128

(d) The smallest mul ple of 94 is ___________.
(i) 2 (ii) 94 (iii) 16 (iv) 14

(e) The mul ple of a number when divided by itself leaves __________ as a
remainder.
(i) 1 (ii) 0 (iii) 2 (iv) 5

3. Do as instructed.
(a) Write two pairs of prime numbers such that the sum of each pair is also a

prime number.
(b) Write any fi ve factors of the following numbers.

(i) 42 (ii) 96 (iii) 28 (iv) 50
(c) Write the fi rst fi ve odd mul ples of the following numbers.

(i) 13 (ii) 9 (iii) 17 (iv) 21
(d) Write the prime factors of the following numbers using the most suitable
method.

(i) 52 (ii) 124 (iii) 17 (iv) 147

(e) Find whether 248 is a mul ple of 4 or not.
(f) Find whether 12 is a factor of 2,460 or not.

(g) Write all the numbers between 1 and 100. Then, circle the prime numbers
and underline the composite numbers.

4. Find the H.C.F. of the following numbers by both lis ng method and common
division method.

(a) 24 and 32 (b) 99 and 110

(c) 14, 50 and 98 (d) 48, 72 and 96
5. Find the L.C.M. of the following numbers by both lis ng method and common

division method.
(a) 24 and 36 (b) 7 and 17

(c) 12, 15 and 30 (d) 4, 5 and 6

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