The figure below shows a black and white table mat that Mrs Lee bought. The diameter of each circle is k cm. (take pi = 22/7) a) find the perimeter of the table mat in terms of k. b) Mrs Lee placed the mat on a table which is 0.85m long and 0.5m wide.[…]
Some questions involving angles involve adding everything up. Here’s an example.
Notice that area of triangle BIE = 1/2 * width (IE) * height (22cm) also, area of triangle CIJ = 1/2 * width (IJ) * height (22cm) the two triangles overlap on the quadrilateral FGHI. so sum of triangles – FGHI = unshaded area. we don’t know IE and IJ but we know that IE[…]
The equal numerator method. Example: Michael and Owen saved some money. 2/3 of Michael’s savings was equal to 1/4 of Owen’s savings. What was the ratio of Owen’s savings to their total savings? When the question is of the form: [fraction] of A is equal to [fraction] of B. You can use the equal numerator[…]
This is a difference / ratio question. In a packet of mixed nuts, 40% are cashew nuts while the rest are peanuts.After 12 cashew nuts are removed from the packet and 24 peanuts are added, the cashew nuts make up 33 1/3% of the nuts in the packet. How many cashew nuts are there in[…]
Four adventurers (Alex, Brook, Chris and Dusty) need to cross a river in a small canoe. The canoe can only carry 100kg. Alex weighs 90kg, Brook weighs 80kg, Chris weighs 60kg and Dusty weighs 40 kg, and they have 20kg of supplies. How do they get across? ===================== Chris and Dusty row across, Dusty returns.[…]
Four people need to cross a rickety rope bridge back to their camp at night. Unfortunately, they only have one flashlight and it only has enough light left for seventeen minutes. The bridge is too dangerous to cross without a flashlight, and it’s only strong enough to support two people at any given time. Each[…]
This is another common interview question, but appropriate for primary school. You have 8 balls which look identical. 7 of them have the same weight, while 1 is heavier. How can you find the heavier ball by using a balance with only 2 weighings? The most common way (but this will require 3 weighings) would[…]
Many students struggling with Mathematics questions often moan about how they will never need to apply the Maths theories when they grow up. I beg to differ. Not only does Mathematics train our mind to think critically, which is very crucial in our adult lives, it definitely opens paths to an exciting stream of job[…]
This is apparently a common interview question: In a bid to have more boys, every family in a certain country will continue to try for children until they have a boy. If they have a girl, they’ll keep trying. If they have one boy, they’ll stop. What will be the proportion of girls to boys[…]