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D:\Surender Prajapati\Books Final_CBSE and ICSE\ICSE\Preparatory_Stage_Maths-5_(31-10-2023)\Open_Files\CHAP_03
              \\November 3, 2023 11:27 AM   Surender Prajapati   Proof 5   Reader _________________________   Date: ___________________74





              Solution:
                    (a)  HCF of 594 and 252.                         (b)  First find the HCF of 144 and 312.


                              252   594 2                                         144    312 2
                                  – 504                                               – 288
                                      90   252 2                                           24  144 6
                                         – 180                                               – 144

                                             72   90 1                                          0
                                                – 72                     HCF of 144 and 312 = 24
                                                   18   72 4            Now, we find HCF of 24 and 396.
                                                     – 72                           24   396 16
                                                        0
                                                                                      – 384
                                                                                           12   24 2
                                                                                             – 24
                                                                                                 0

                         Thus, HCF of 252 and 594 is 18.                 HCF of 24 and 396 is 12.

                                                                        Thus, HCF of 144, 312 and 396 is 12.
              Example 5: Two  tankers contain  675 litres and  450 litres of  water respectively. Find  the

              maximum capacity of a container which can measure the water of both the tankers exactly.
              Solution:     The maximum  capacity  of a  container  which  can  measure the  water  of both
                            the tankers when used an exact number of times will be the HCF of 675 and

                            450. So, we have to find HCF of 675 and 450.
                            Factors of 675 = 3 × 3 × 3 × 5 × 5                                   3 675          3 450
                                                                                                 3 225
                                                                                                                3 150
                            Factors of 450 = 3 × 3 × 2 × 5 × 5                                   3 75           2 50
                            The common factors of 675 and 450 are 3, 3, 5 and 5.                 5 25           5 25

                            So, HCF of 675 and 450 = 3 × 3 × 5 × 5 = 225.                        5   5          5   5
                                                                                                     1
                                                                                                                    1
                            Thus,  the maximum capacity  of  a container  which  can
                            measure the water of both the tankers is 225 litres.


                       Practice Time 3E


                1.  Find the common factors of the following numbers.

                    (a)  18, 24             (b)  21, 36              (c)  48, 56              (d)  72, 102
                2.  Find the HCF using the common factors method.

                    (a)  15, 20             (b)  12, 18              (c)  33, 55              (d)  35, 42

                    (e)  42, 64              (f)  50, 80             (g)  18, 24, 32          (h)  32, 48, 72
                     (i)  15, 30, 75         (j)  28, 42, 70         (k)  50, 75, 100          (l)  21, 56, 35


              Mathematics-5                                                                                          71
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