The area of a field in the shape of a trapezium measures 1440sq m. The perpendicular distance between its parallel sides is 24cm. If the ratio of the sides is 5:3, the length of the longer parallel side is:

Area of field =  $\frac{1}{2}*5x+3x*24$ = 96x sq.m  

96x = 1440       => x = $\frac{1440}{96}$ = 15  

Hence, the length of longer parallel side = 5x = 75m