The answer is nine: 17 minus 8 is 9
Solution:
Given:

To get sin 240 degrees:
240 degrees falls in the third quadrant.
In the third quadrant, only tangent is positive. Hence, sin 240 will be negative.

Using the trigonometric identity;

Hence,

To get cos 240 degrees:
240 degrees falls in the third quadrant.
In the third quadrant, only tangent is positive. Hence, cos 240 will be negative.

Using the trigonometric identity;

Hence,

To get tan 240 degrees:
240 degrees falls in the third quadrant.
In the third quadrant, only tangent is positive. Hence, tan 240 will be positive.

Using the trigonometric identity;

Hence,

To get cosec 240 degrees:

To get sec 240 degrees:

To get cot 240 degrees:
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➷ T
B
✽ Ok, so B is the number of boys and T is the number of teachers.
➷ 

✽ Then solve the second equation for B.
➷ 
✽ Plug into the first equation to find T.
➷ 

✽
➶ Hope This Helps You!
➶ Good Luck (:
➶ Have A Great Day ^-^
↬ May ♡