Number System Questions for Competitive Exams

A rational number between $${3\over4} $$ and $${3\over8} $$ is :

In a school $${1\over10} $$ of the boys are same in number as $${1\over4}$$ of the girls and  $${5\over8} $$ of the girls are same in number as $${1\over4}$$   of the boys. The ratio of the boys to girls in that school is: 

If * means adding 6 times the second number to the first number then ( 1 * 2 ) *   3 equals : 

How many even three-digit numbers can be formed from the digits 1 , 2 , 5 , 6 and 9 without repeating any of the digits? 

What is the sum of two consecutive even numbers, the difference of whose square is 84? 

A man spends  $${1\over 3}$$ of his income on food,   $${2\over 5}$$  of his income house rent and   $${1\over 5}$$ of his income on clothes. If he still has Rs. 400 left with him, his income is: 

How many natural numbers divisible by 7 are there between 3 and 200? 

A number when divided by 296 gives a remainder 75. When the same number is divided by 37 the remainder will be: 

Which of the following is the largest fraction   $${6\over7},{5\over6},{7\over8},{4\over5} ?$$ 

Two number 11284 and 7655, when divided by a certain number of three digits, leaves the same remainder. The sum of digits of such a three - digits number is: