Assuming that the balls are not replaced;

= 5/42
(the numbers are decreasing in the denominator as you are presumably taking out the red balls. In the denominator, there is one less ball each time since you took out a red one).
Therefore, the probability of selected 4 red balls consecutively without replacement is 5/42.
Hope I Helped :)
(a) 1,1 (b) 3,2 (c) 3,2 (d) 1,5
First of all you have to convert kg to grams
so there is 1 kg in 1000g
.4 kg is 400g
1000+400= 1400g
1400-650 = 750 kg
that's your final answer
220 people per year
2600-1500= 1100/5 = 220
y² = 8y - 15 (alternate angles are equal)
y² - 8y + 15 = 0
(y - 5)(y - 3) = 0
y = 5 or 3
x + 8y - 15 = 180 (angles in a straight line add up to 180)
when y = 5
x + 40 - 15 = 180
x = 155°
when y = 3
x + 24 - 15 = 180
x = 171°