Question

the length of a rectangle is 6m less then three time its breadth. if the perimeter is 148m ,then its length is_______.
(a)60m
(b)66m
(c)54m
what is the correct answer explain me please

Answer 1

$b = x \\ l = 3x - 6 \\ p = 2(l + b) \\ 148 = 2(3x - 6 + x) \\ 148 = 2(4x - 6) \\ 148 = 8x - 12 \\ 148 + 12 = 8x \\ 160 = 8x \\ x = \frac{160}{8} \\ x = 20 \\ b = 20m \\ l = 3x - 6 \\ \: \: \: = 3 \times 20 - 6 \\ \: \: \: \: = 60 - 6 \\ \: \: \: \: \: = 54m$

Answer 2

Breadth of rectangle = x
Length of rectangle = 3x-6
Perimeter of rectangle = 148

Perimeter of rectangle = 2(l+b)
148 = 2 ( 3x-6+x)
148=2 (4x-6)
148÷2=4x-6
74=4x-6
74+6=4x
80=4x
80÷4=x
X=20
Now,
Breath=20m
Length=3(20)-6
60-6
=74m
(C) is correct ans