It's simple arithmetic. The Answer is 604661760000000000000000000000000000000000000000000000000000000000000000000000000000 and in scientific notation
60466176 x 10⁸³
P(at least 5 rolls until 1) = P(4 rolls are not 1) = 5/6 x 5/6 x 5/6 x 5/6 = 0.4823 (4sf)
Fewer than 7 rolls to get second 1 after first takes 3 rolls means second occurs on 4th, 5th or 6th roll
The probability of each of these is 1/6, 5/6 x 1/6 and 5/6 x 5/6 x 1/6 respectively.
P(second 1 on 4th, 5th or 6th roll) = 1/6 + 5/36 + 25/216 = 91/216 = 0.4213 (4sf)
Wrapping paper design with the elements numbered bisected angle
C= 50y+20x
Where y is the number of boxes holding 50 pieces each and x is the number of boxes holding 20 pieces each.