Simultaneous Equations Word Problems
Maths: Edexcel A Level Pure Maths, topic 2.2.9
Worded Problems
John has twice as many sweets as Katie. In total they have 30 sweets. How many sweets do they each have?
Set algebra to represent number of sweets each person has
1st equation says "John has twice as many sweets as Katie"
2nd equation says "in total they have 30 sweets"
Label the equations
Solve by substituting (1) into (2)
Simplify
This is the solution for K
To find the solution for J, substitute K back into equation (1)
Solve to find solution for J
Remember the meaning of the algebra
Test yourself on Simultaneous Equations Word Problems
If there are blue (b) and red (r) balls in a bag, what is an equation for the total (T) number of balls in the bag?
If there are 10 more red (r) balls than blue (b) balls in a bag, which is NOT an equation for the total (T) number of balls in the bag?
If there are 15 more red (r) balls than blue (b) balls in a bag, which is NOT an equation for the total (T) number of balls in the bag?
David (D) has twice as many sweets as Sue (S). In total they have 40 sweets. Which is the correct set of simultaneous equations to solve?
David (D) has twice as many sweets as Sue (S). In total they have 50 sweets. Which is the correct set of simultaneous equations to solve?