(18+4i)+(-11+23i) Express your answer in the form (a+bi)

If 10 men take 18 days to mow 60 acres of grass, how long will 15 men take to mow 80 acres?

Which one is true about the hexagons ?

Aroulette wheel has 38 slots in which the ball can land. two of the slots are green, 18 are red, and 18 are black. the ball is equally likely to land in any slot. the roulette wheel is going to be spun twice, and the outcomes of the two spins are independent.the probability that it lands one time on red and another time on black in any order is(a) 0.5 (b) 0.25 (c) 0.4488 (d) 0.2244