Question

The length and breadth of a playground are 75m 20cm and 34m

80 cm respectively. Find:

a) the cost of levelling it at the rate of Rs. 1.50 per square metre.

b) how long will a boy take to go three rounds of the field if he walks

at the rate of 1.5m per second.

ii) Find the mean and median of the following data:

a) 10,12,15,14,14,13,12,12,14,11

b) 22,21,15,45,21,26,50​

Answer 1

Answer:

Length of playground     = 75m 20cm = 7520cm

Breadth of playground    = 34m 80cm = 3480cm

Area of rectangle              = length x breadth

Area of playground         = 7520 x 3480

                                           = 26169600cm2 = 261696m2

Perimeter of rectangle      = 2 ( l +b )

Perimeter of playground = 2 ( 7520 + 3480 )

                                          = 2 x 11000

                                          = 22000cm = 220m

1. Cost of levelling for 1m2         = 1ruppee 50paise = 1.50ruppees

    Cost of leveling for 261696m2 = 261696 x 1.50

                                                       = Rs 392544

2. Length around the field a boy takes to walk 1 time     = 220m

    Length around the field a boy takes to walk 3 times   = 220 x 3

                                                                                              = 660m

   Time he will take if he walks at the rate of 1.5 second = 660 x 1.5

                                                                                              = 990 seconds = 16 minutes 5 seconds