Solve the system of equation by using elimination: 

Farmer Joe had 35 customers for the whole morning. He knew 20 of them. How many new customers did he meet today ?

Read the problem carefully multiple times in order to understand it.

The budget for a school band was   in 2010 . The budget decreased by  from 2010 to 2011 and then increased by  from 2011 to 2012 . Which of the following expressions represents the budget, in dollars, for the school band in 2012?

Note:
The concept of percentages can be a little tricky. But we just need to remember a few basic things to get going. This is the standard way of finding the value after increasing or decreasing a quantity by a certain percentage

The perimeter of a trapezium is 52cm .Its non parallel sides are equal to 10cm each and its altitude is 8cm. Find the area of the trapezium ?

If the denominator of a certain fraction increased by 1 and the numerator by 2.The fraction becomes equal to 5/8 and if the numerator and denominator are diminished by 1, the fraction becomes equal to 1⁄2. Find the fraction.

Three cylinders each of height 16 cm and radius of base 4 cm are placed on a plane so that each cylinder touches the other two. What is the volume of the region enclosed between the three cylinders?

The parallel sides of an isosceles trapezium are 16cm and 28cm and equal sides are 24cm each. Find the area ?

The sum of the digits of a two-digit number is 7. If the digits are reversed, the number is reduced by 27. Find the number?

Venu has as many sisters as he has brothers. If Karuna, Venu’s sister has thrice as many brothers as she has sisters, then Venu has how many sisters?

A pit 10 m long and 2 m wide is filled with 4.8 cubic m. of sand. What is the depth of the pit?

The circumference of Earth is estimated to be 40,030 kilometers at the equator. Which of the following best approximates the diameter, in miles, of Earth's equator? (1 kilometer   miles)

Note:
There are many other units of length which are often used. For example: inch, foot, yard, centimetre, parsec, lightyear, nanometre, etc. They measure anything between atoms to a galaxy.
Some relations between them are given by
1 kilometer = 39370.0787 inches = 3280.84 feet = 100000 centimetre
1 mile = 63357 inches = 5279.75 feet = 160926.94 centimetre

Length of the fence of a trapezium shaped field ABCD is 120m. If BC = 48m , CD = 17m and AD = 40m , Find the area of this field. Side AB is perpendicular to the parallel sides AD and BC.

Mukesh has some goats and hens in his shed. Upon counting, Mukesh found that the total number of legs is 112 and the total number of heads is 40. Find the number of hens in his shed.

The capacity of a cup is 300 ml. The capacity of a jug is twice that of a cup. What is the capacity of 3 cups and 3 jugs?

A mother said to her son, ‘the sum of our present ages is twice my age 12 years ago and nine years hence, the sum of our ages will be thrice my age 14 years ago’. What is her son’s present age?

The cross section of a canal is a trapezium is shape. If the canal is 10m wide at the top and 6m wide at the bottom and the area of cross section is 840sq.m. Find the depth of the canal?