This is how i will come out with a solution for the question on Miss Seow her pupils:
For these kind of questions, we don’t really need fancy methods or drawing models to solve. We can solve it logically. Let’s just discuss and picture some scenarios and we will arrive at the answer..
Let’s imagine Miss Seow’s group of children seated in a circle and Miss Seow has decided to go one full round around them to distribute some chocolates to them. If she gives each of them 5 chocolates, she will have 128 chocolates left in her paper bag where she keeps the chocolates..
Now, suppose we don’t know how many children are there seated in the circle yet, lets just continue to use some imagination..
Miss Seow now decides to give 13 chocolates each, instead of giving 5. Like it says so in the question “if she gives 5…… then if she gives 13…….” remember that this is if she gives. The thing is, she didn’t actually give.
So let’s get back to the children and Miss Seow. The children already have 5 chocolates in their hand (assuming they havent eaten them yet), and Miss Seow wants them to have 13 each instead of 5, so what Miss Seow will do, is she will make a second round around the children, and give an additional 8 chocolates to each child now, so that 5 + 8 = 13.
After finishing the 2nd round, she realises now that in the paper bag, she has 40 chocolates left. Before distribution in the 2nd round, she had 128, but now she had 40 left. So that means, in the second round, she gave away 128 – 40 = 88 chocolates!
And remember that in the second round she had to give an additional 8? So if she gave away 88 chocolates in the second round and each child received 8, that means that there were 11 children! ( check that 88 divided by 8 is 11)
There we have our answer, no need for models or fancy methods. Hope this helps because as a tutor, we know that more often that not, models do over-complicate things for some questions and they put our students in more confusion than they already are.
We provide coaching for small, focus groups of students at Future Achievers Hub at Tampines Junction.
Do check out:
www.futureachievers.com.sg
or call us at +65 83325521,
for more info and sign up for Free Classes now!