Answer:
1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
Step-by-step explanation:
The order in which the teachers are chosen is not important, which means that the combinations formula is used to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
In this question:
1 from a set of 2(Either Mrs. Vera or Mr. Jan).
3 from a set of 18 - 2 = 16. So

1120 combinations of four teachers include exactly one of either Mrs. Vera or Mr. Jan.
The answer is 5.
Step-by-step explanation:
To find the interquartile range you must look at the median and the upper and lower halves of the data. The median (12) to the upper half of the data (15) is 3. Next, look at the median (12) to the lower half of the data (10) it is 2. We then add 2 and 3 to get the interquartile range of 5.
Answer:
20x+68
Step-by-step explanation:
Answer:
Perimeter of rectangle = 30 cm
Step-by-step explanation:
Perimeter of rectangle = (length + width) x 2
-- width or breadth --
Perimeter
= (10 + 5) * 2
= 15 * 2
= 30 cm