They could have assembled total 336 different possible crews.
<em><u>Explanation</u></em>
Total number of trained pilots is 9 and geologists is 4.
The crew should be consisted of 2 pilots and 1 geologist. That means, <u>2 pilots are chosen from total 9 and 1 geologist is chosen from total 4</u>.
Number of ways for choosing 2 pilots from 9 and
Number of ways for choosing 1 geologist from 4
So, the total possible number of different crews they could have assembled
Answer:
No, Chancee mixed up the variables, the correct solution is that x must be between 20 and 40 and y must be between 0 and 10.
Step-by-step explanation:
Here, x and y are positive integers,
Such that, their sum is not more than 40,
i.e. x + y ≤ 40 where x, y ≥ 0,
⇒ y ≤ 40 - x ...............(1),
Their difference is at least 20,
i.e. x - y ≥ 20
-y ≥ 20 - x
⇒ y ≤ x - 20 ............(2),
Graphing y ≤ 40 - x :
Related equation of inequality (1),
y = 40 - x
if x = 0, y = 40,
if y = 0, 0 = 40 - x ⇒ x = 40,
'≤' represents a solid line,
Join the points (0, 40) and (40, 0) by solid line.
Graphing y ≤ x - 20:
Related equation of inequality (1),
y = x - 20,
if x = 0, y = -20,
if y = 0, 0 = x - 20 ⇒ x = 20,
'≤' represents a solid line,
Join the points (0, -20) and (20, 0) by solid line.
By graphing we obtained a feasible region that is the solution of the system of inequalities (1) and (2) ( shown below ),
In which,
20 ≤ x ≤ 40 and 0 ≤ y ≤ 30
Hence, Chancee did not find the correct solution.
