Each year a school organises a concert. (a) i) in 2004 the cost of organising the concert was $385.
In 2005 the cost was 10% less than in 2004.
Calculate the cost in 2005.
ii) The cost of $385 in 2004 was 10% more than the cost in 2003.
Calculate the cost in 2003.
(b) i) In 2006 the number of tickets sold was 210.
The ratio Number of adult tickets: Number of student tickets was 23:19.
How many adult tickets were sold?
ii) Adult tickets were $2.50 each and student tickets were $1.50 each.
Calculate the total amount received from selling the tickets.
iii) In 2006 the cost of organising the concert was $410.
Calculate the percentage profit in 2006.
(c) In 2007, the number of tickets sold was again 210.
Adult tickets were $2.60 each and student tickets were $1.40 each.
The total amount received from selling the 210 tickets was $480.
How many student tickets were sold?
Cambridge IGCSF

Find two rational expressions that have the difference of 2-n/n-4

Which point is a solution to y s 4x + 5?

Airplane speeds are measured in three different ways: (1) indicated speed, (2) true speed, and (3) ground speed. the indicated airspeed is the airspeed given by an instrument called an airspeed indicator. a plane’s indicated airspeed is different from its true airspeed because the indicator is affected by temperature changes and different altitudes of air pressure. the true airspeed is the speed of the airplane relative to the wind. ground speed is the speed of the airplane relative to the ground. for example, a plane flying at a true airspeed of 150 knots into a headwind of 25 knots will have a ground speed of 125 knots. the problems below refer to static and dynamic pressure. static pressure is used when a body is in motion or at rest at a constant speed and direction. dynamic pressure is used when a body in motion changes speed or direction or both. a gauge compares these pressures, giving pilots an indicated airspeed. in problem #s 1 and 2, use the following information. the indicated airspeed s (in knots) of an airplane is given by an airspeed indicator that measures the difference p (in inches of mercury) between the static and dynamic pressures. the relationship between s and p can be modeled by s=136.4p√+4.5. 1. find the differential pressure when the indicated airspeed is 157 knots. 2. find the change in the differential pressure of an airplane that was traveling at 218 knots and slowed down to195 knots. in problem #s 3 and 4, use the following information. the true airspeed t (in knots) of an airplane can be modeled by t=(1+a50,000) ⋅ s, where a is the altitude (in feet) and s is the indicated airspeed (in knots). 3. write the equation for true airspeed t in terms of altitude and differential pressure p. 4. a plane is flying with a true airspeed of 280 knots at an altitude of 20,000 feet. estimate the differential pressure. explain why you think your estimate is correct.