Solution:

$16

Solution:

68

Explanation:
(9 * 7) + 5 = 68

Solution:

Augustus and Joshua play all the three sports. Stacy plays none.

This is when we have assumed that girls do not play football at all. If by any means, the school has a girl's football league, all we know is that one of the three play no sports at all and the others play all the three.

Solution:

10 percent of student study all four subjects.

Solution:

According to the given data,

6 x number of notebooks + 5 x number of notepads = 32

Here, we are sure that the number of notebooks and the number of notepads can only result in whole numbers. Thus, the respective values will be 2 and 4.

Solution:

12,345,678,987,654,321

(its amazing and awesome)

Solution:

40

Cost of each alphabet is 5

Solution:

1

As stated
1=6 => 6=1

Solution:

1st fish tank-> 5

2nd fish tank-> 7

Solution:

All other shapes are quadrilaterals, while a hexagon has six sides.