There are four ways they can land.
1. Head on the first coin, head on the second coin.
2. Head on the first coin, tail on the second coin.
3. Tail on the first coin, head on the second coin.
4. Tail on the first coin, tail on the second coin.

Those four are equally likely, so the probability of 
getting two heads is 1 time out of 4, or 1/4, or
25 times out of 100.  [Take 1/4 of 100]

Answer; 25.

Edwin