Hi Ruru....thanks for your help.


I managed to solve this problem using the assuming method too after having my dinner....Ha ha....can't work on on empty stomach.

If all notes are $50, 90 x $50 =$4500

remaining money (which are the halves of the $100) will be
5250 - 4500 = 750

750/50 = 15 (number of $100)

90 - 15 = 75 (ans)

Based it on one of the questions ( think its the legs of cows and chickens or something) in this thread. I'm so glad there's a forum like this for 'challenged' aunty like me

Hi…can anyone help me with the following problem?


Uncle Sam paid $5250 for a plasma television. He paid the exact amount in $1oo and $50. He gave the cashier 90 notes in all. How many of them were $50 notes?

Ans: 75

I managed to solve it with the following ‘expression’:

100u + (90 x 50) - 50u = 5250
50u + 4500 = 5250
u = 750/50 = 15

therefore, no. of $50 = 90 - 15 = 75

Am trying to help coach my nephew as the parents can’t afford tuition (Dad was retrenched last year). But I don’t know how to explain to my nephew using the modeling method.