Page 1 - CBQ CH 5
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SAI International School



                                                          Class:  VI

                                                                           Mathematics


             CH 5 PRIME TIME- CBQ

             1       Which of the following numbers is divisible by all of 2, 4, 5, 8 and 10? ‘
                     (a) 472(b) 3522(c) 9000(d) 996
             2       How many multiples of 12 are there between 1 and 100?
                        (a) 12 (b)8  (c) 24 (d) 6
             3       Assertion (A): The number 28 is a perfect number.
                     Reason(R): A number for which the sum of all its factors is equal to twice the number is
                     called a perfect number.
                     a) Both A and R are true and R is the correct explanation of A.
                     b) Both A and R are true but R is not the correct explanation of A.
                     c) A is true but R is false.
                     d) A is false but R is true.
             4       State true or false and justify your answer by giving an example.
                     There are no perfect number between 1 and 10.
             5       Fill in the blanks:
                     ____________are pairs of primes having a difference of 2.
             6       Gita and Mita are playing the treasure hunting game. Mita has kept treasures on
                     numbers 32 and 80 on a line. What sizes of jumps will Gita take to land on both
                     numbers?


             7       The prime factorisation of a number has one 2, two 3s, and one 11. What is the number?

             8       Who am I?  I am a number less than 40. One of my factors is 7. The sum of my digits is 8.

             9       A number is divisible by both 5 and 12. By which other number will that number be
                     always divisible?
             10      Find the smallest natural number that has six factors in all.
             11      Find any three numbers that are multiples of 25 but not multiples of 50.

             12      2024 is a leap year (as February has 29 days). Leap years occur in the years that are
                     multiples of 4, except for those years that are evenly divisible by 100 but not 400.
                        a.  From the year you were born till now, which years were leap years?
                        b.   From the year 2024 till 2099, how many leap years are there?
             13      In a school library, there are 780 books of English and 364 books of Science. Ms. Kiran,
                     the librarian of the school wants to store these books in shelves such that each shelf
                     should have the same number of books of each subject.

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