Solution:

A kangaroo

Solution:

'five'

Its the count of alphabet

Solution:

One Minute building

building 62 => Sixty second building => One minute building

Solution:

The wise man told them to switch the horses and then race. In this manner, both of them will be willing to race as fast as they can to prove that the other horse (his own horse) is slow.

Solution:

28 =>1+2+4+7+14

cannot be 1 (as number cannot be included)

Solution:

charles put the ring into the box, secure it with one of your locks, and send the box to the girl firend.
She should then attach one of his own locks and return it. When you receive it again, remove your lock and send it back with her lock. Now she can unlock his own lock and retrieve the object.

Solution:

Michelangelo juggles the diamonds across while crossing the bridge.

Solution:

The woman told him to take out one nut each from the rest of the wheels and use them.

Solution:

Pages 19, 20, 23, 37, 38, & 42 will also be missing

Solution:

There is no mention if you can use sign or not and thus the only possible way to get this is as follows:

(15 - 9) + (13 - 7) + (7 - 1) + (9 - 1) + (13 - 9)

If you solve inside the brackets, you will get the following equation
6 + 6 + 6 + 8 + 4
Adding all these numbers, you will get 30 which is the required sum.

Solution:

This statement is true but only in a specific case i.e. if both of the siblings continue to live till the day the younger is as old as the elder one was during the time of their birth.