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[…]
Insects There are two groups of insects. In the first group, including insects such as cockroaches, grasshoppers, dragonflies and bugs, the wings develop gradually on the outside of the body and get larger at each moult until they are fully formed. The young stages of these insects are called nymphs and they usually resemble the[…]
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[…]
The inner core of the Earth is not molten. It is actually a solid core of mostly Nickel and Iron, and is roughly 1200km in diameter! The inner core of the Earth also contains much gold, platinum and other precious metals. Unfortunately there isn’t a way to get to it yet.
It is not true that different sections of the tongue are exclusively responsible for different basic tastes. This is a misconception that has persisted since 1901 and has been illustrated with a schematic map of the tongue, with certain parts of the tongue labeled for each taste. Although widely taught in schools, this was scientifically[…]
There are two main groups of bats – Megachiroptera and Microchiroptera. The Megachiroptera are medium-sized to large bats that eat fruits, nectar, and sometimes small animals or fish. These species have pronounced visual centers and big eyes as they use senses of vision and smell to capture their prey. For example, Flying Foxes are able[…]