Permutation & combination

please answer me.

for2. there are 5 vowels ( E U A I O) and 5 consonants(R G L T N). the word contains 5 even places and 5 odd places. 5 even places can be filled by 5 vowels in 5P5 ways and similiarly 5 odd places by 5 other consonants in 5P5 ways ..

Therefore, 5P5 * 5P5 = 5! * 5! = 120*120=14400

please solve my first problem.....

if odds in favor of Ais 5:7 & odds against B is 9:6 of solving a problem then probability that a problem can be solved is.

ans:117/180.