If  3 x +2 y = 5 a + b, and 4 x - 3 y = a + 7 b, then x is equal to -

Let  be defined for all numbers a,b,c, and d by = ac - bd. If x = ,
what is the value of ?

In a group of m workers, if b workers earn per week and the rest earn half that amount each, which of the following represents the total number of rupees paid to the entire group of workers in a week ?

If n is the first of two consecutive odd integers, and if the difference of their squares is 120, which of the following equations can be used to find their values ?

A certain type of board is sold only in lengths of multiplies of 2 metres.  The shortest board sold is 6 metres and the longest is 24 metres.  A builder needs a large quantity of this type of board in metres lengths.  For minimum waste, the lengths to be ordered should be-

A snapshot measures It is to be enlarged so that the longer dimension will be 4 inches.   The length of the enlarged shorter dimension will be -

What is the value of the expression
                                                    

A zoo has 4 times as many gorillas as tigers.  There are 4 more tigers than there are zebras at the zoo.  If z represents the number of zebras, in terms of z, how many gorillas are in the zoo ?