Which of the following represents a correct proportion?

What is the probability of forming word from the letters of word “IMPEACH” such that all vowels come together?

A and B can do a piece of work in 28 and 35 days respectively. They began to work together but A leaves after sometime and B completed remaining work in 17 days. After how many days did A leave? 

The difference between C.I and S.I for 2 years is Rs. 9. Find the sum (in Rs.) if the rate is 15% per annum.

The mean of 12 observations is 15. One more observation is included and the new mean becomes 16. The 13th observation is

If A:B is 2:5 and B:C is 3:4, what is A:C? 

A man sells two chairs at Rs. 120 each and by doing so he gains 25% on one chair and loses 25% on the other. His loss on the whole in Rs.is

If  $$ {x^{\sqrt{x}}}={({x{\sqrt{x}}})^{x}}$$, then the find the value of x