Monetary difference
Al, Bertie, Chris and Di have sums of money totalling £150... What is the difference between the amount Al and Di have?
Age
14 to 16
Challenge level
Problem
Al, Bertie, Chris and Di have sums of money totalling £150.
Al and Bertie have £55 between them and Al and Chris have £65 between them.
What is the difference between the amounts that Al and Di have?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
Student Solutions
Answer: £30
A + B + C + D = £150
A + B = £55 $\therefore$ C + D = £150 $-$ £55 = £95
A + C = £65 which is £30 less than £95 = D + C
so D is £30 more than A