Perimeter of a rectangle is 2.4 m less than 2/5 of the perimeter of a square.if the perimeter of the square is 40 m,Find the length and breadth of the rectangle given that breadth is 1/3 of the length.(7th class math)

Perimeter of a rectangle is 2.4 m less than 2/5 of the perimeter of a square .if the perimeter of the square is 40 m. Find the length and breadth of the rectangle given that breadth is 1/3 of the length.

Solution: Given , Perimeter of square = 40 m

                                              Breadth   = 1/3 x length

                 According to question given that,

                 Perimeter of a rectangle is 2.4 m less than 2/5 of the perimeter of a square.

                 Perimeter of rectangle = 2/5 x perimeter of a square - 2.4 m

                                                      = 2/5 x 40(given) - 2.4 

                                                      = 16 - 2.4

                                                      = 13.6

                 perimeter of rectangle = 2(Length + Breadth)

                                              13.6 = 2(Length + Breadth)

                                           13.6/2 = Length + Breadth

                         Length + Breadth = 6.8

                  According to question,put the values

                        3 Breadth + Breadth = 6.8

                                          (Breadth = 1/3 x Length)

                                          (3 Breadth = Length)

                              4 Breadth = 6.8

                                 Breadth = 6.8/4

                                 Breadth = 1.7

                    then,    Breadth = 1/3 x Length

                     put the value,

                                      1.7 = 1/3 x length

                               Length = 1.7 x 3

                               Length = 5.1