=> first Convert 13 1/2 to improper fraction...
=> 13 1/2 = 13*2 +1 /2 = 27/2
=> 27/2 ÷ 3/4
=> 27/2/3/4
=> for dividing fractions we take the reciprocal of one fraction and then multiply ..
=> 27/2 * 4/3
=> to multiply fractions we multiply the numerators ( top numbers ) with each other and the denominators (bottom numbers ) also the same way ...
=> 27*4/2*3
=> 108/6 => 18 ..
Hope it helps !!!