$$ {{2^n+2^{n-1}}\over {2^{n+1} -2^n}}=?$$

If $$ {x+{1\over x}}=2$$ then find out the value of $${2x^2+2}\over{3x^2+5x+3}$$

The ratio of two numbers is 2: 3 and their L.C.M is 48.  What is the number?

An item is sold at two successive gains of 30% and 20%. If the final selling price is Rs 31200, then what is the cost price (in Rs)?

The cost price of 60 articles is same as the selling price of x articles. If there is a profit of 20%, then what is the value of x?

While selling an article for Rs 18450, a person suffered a loss of 50%. At what price he should have sold the article (in Rs) to earn a profit of 50%?

A box contains 56 in the form of coins of one rupee, 50 paise and 25 paise. The number of 50 paise coins is double the number of 25 paise coins and four times the number of one rupee coins. How many 50 paise  coins are there in the box?

In an examination, 93% of students passed and 252 failed. The total number of students appearing at the examination was: