2017 PSLE MATHS QUESTION

 

You might have heard about the tricky 2017 PSLE Maths question that has been circulating online. If not, this is the question:

 

Jess wants 200 ribbons of length 110cm for a party. 

However, the ribbons were sold at 25m per tape. 

How many tapes will Jess need?

 

At first glance, the solution seems straightforward.

 

Length of ribbon needed -> 200 x 110 = 22000cm

Length of 1 tape -> 25m = 2500cm

Number of tapes needed -> 22000 / 2500 = 8.8 = 9 (when rounded up)

 

However, the above solution is incorrect. We are assuming that we can join the remaining ribbons from each tape to form new 110cm ribbons.

The correct working is:

 

Length of 1 tape -> 25m = 2500cm

Number of ribbons that can be obtained from 1 tape -> 2500 / 110 = 22.72 = 22 (when rounded down)

Number of tapes needed -> 200 / 22 = 9.09 = 10 (when rounded up)

 

Our P5 pupils covered these types of questions in Term 4. Click the image below to see if you can use this concept to solve similar types of questions.