A worded problem

Question

Redlands School sent x students to a revision day. St Samuels School sent twice as many students as Redlands School. Francis Long School sent 7 fewer students than Redlands School. Each student paid £15 for the revision day. The students paid a total of £1155. How many students were sent by each school to the revision day? (I know the answers are Redlands school-21, St Samuels-42, francis-14, but I want to know how to work this out. could someone help me?)

Answer 1

Hi

here is the solution.Given

Number of Students of Redlands school= x

Number of Students of St Samuels School = 2*x      (twice of Redlands school)

Number of students of Francis Long School = x-7     (7 fewer than redlands school)

Total number of students = x + 2x + (x-7) = 4x-7

Each student paid =£15

total paid = £15 * (4x-7) which is equal to £1155

so we get  4x -7 = 1155/15

4x-7=77

4x= 77+ 7 =84

x = 84/4 = 21

Number of students of Redlands school = x = 21

Number of Students of St Samuels School = 2*x  = 2*21 = 42
Number of students of Francis Long School = x-7 = 21 -7 =14

 

 

 

Answer 2

Hi Saiyan,

 

You have to translate the English into math. . .

 

Let X = the number of Redlands students

 

St. Samuels sent twice as many--> 2X

 

Francis Long sent 7 fewer than Redlands--> X - 7

 

Each student paid 15 euros so you have to multiply the number of students times 15 to get the amount paid:

 

15X + 15(2X) + 15(X-7) = 1155

 

15X + 30X + 15X - 105 = 1155

 

Now combine like terms and solve for X.

 

Have fun.

 

Dan