Suppose a fair die is cast seven times to obtain a sequence of seven numbers.
(a) describe the universal set of sequences in words.
(b) how many sequences have each entry either a 3 or a 5?
(c) if a is the subset of sequences containing no 1’s, describe the set ac in words. (d) find the number of elements in the set a.
(e) how many elements are in the set ac?

Answer: d. 39 cmin the diagram, the approximate length of the minor arc de is 39 centimetres.step-by-step explanation: the formula for the length of an arc in a circle is as displayed below.let the length of the minor arc de = xx = 2( pi )r × angle of sector / 360°from this, we will substitute the values given from the problem into the formula to obtain the length of the minor arc de.x = 2( pi )r × angle of sector / 360°r = radius = 25cmpi as an approximate value = 3.14angle of sector = 120°x = 2( 3.14 )( 25 ) × 120° / 360°x = 157 × 1 / 4x = 39.25x = 39 ( rounded to the nearest whole number as an approximate value )