Math
State the value of Euler’s constant, e , correct to 4 significant figures.
2.718
Describe the change (if any) to red blood cells in seawater.
shrink
Water moves from the high water potential inside the cell to the low water potential of the salty seawater. This loss of water causes the cell to shrivel, a process called crenation.
Aside from Gold, name the only other non-silvery-grey metal.
Copper
You hear an echo 2 seconds later. If sound is 340 m/s, how far away is the wall?
340m
Five students, A, B, C, D and E, ran a race.
* A finished before B.
* C finished after D.
* E finished after B but before C.
Who finished last?
C finished last.
There are 10 people at a party. If each person shakes hands with every other person exactly once, how many handshakes occur in total?
45 handshakes
Name two hormones possibly released when you are stressed.
cortisol and adrenaline/epinephrine
Released by the adrenal glands, cortisol increases glucose in the bloodstream, enhances brain energy usage, and repairs tissues to manage stressful situations. Adrenaline is also released for rapid "fight-or-flight" responses.
What is the chemical name of the "cloudyness" formed in the limewater test?
calcium carbonate
You look through a standard periscope (two 450 mirrors). If you raise your right hand, which hand does the reflection raise?
Right hand
In a single mirror, the image is inverted. In a periscope, the second mirror inverts the first inversion. The result? You see yourself exactly as you are (upright and non-inverted).
Look at the following repeating sequence of a robot:
*Move Forward, Turn Left. Move Forward, Turn Left, ...
What shape will it eventually complete?
Square
Which one of the following is a factor of 2^10 - 1?
A. 21 B. 31 C. 41 D. 51
B. 31
using the difference of 2 squares,
2^10 - 1 = (2^5 +1)(2^5 -1) = 33 x 31
What specific type of white blood cell "remembers" a past virus?
Lymphocytes provide targeted immunity:
B-cells: Produce antibodies to neutralize invaders.
T-cells: Attack infected cells directly and coordinate the response.
You have two identical balloons: one filled with Hydrogen and one with Helium. Which one will stay afloat longer in a room?
Helium
Hydrogen molecules are smaller than Helium atoms, and have a lower relative molecular mass. Because of this, hydrogen diffuses through the microscopic pores of the balloon material faster, causing it to deflate and sink sooner.
You are on a sailboat with a giant fan fixed on the deck. If you point the fan directly at the sail, which way does the boat move?
Backwards (or stays still)
the fan pushes air forward (Action), which pushes the fan (and the boat) backward (Reaction). The air hitting the sail is a secondary force that usually cancels out or loses to the initial recoil.
A sequence is written on the board:
1, 11, 21, 1211, 111221, ....
The sequence begins with 1. Each term after describes the one before it
(for example, “one 1,” “two 1s,” and so on).
What is the next term in the sequence?
A: 111222 B: 312211 C: 132211 D:311122
B. Try reading 111221 aloud
Ali measures three sides of a rectangle and gets a total of 52 cm.
Ben measures three sides of the same rectangle and gets a total of 44 cm.
What is the perimeter of the rectangle?
64 cm
2L + B = 52 and 2B + L = 44
Solving, we get B = 12 and L = 20
Besides genetic factors, what determines one's fingerprints?
Environmental factors
such as amniotic fluid density and fetal movement, especially between the third and sixth months of pregnancy
Name the Noble Gas used in speed camera flashes that can react with fluorine.
Xenon
You are in a car turning a sharp left. In which direction will a helium balloon, floating in the car, tilt?
Left.
Air is heavier than helium. Inertia pushes the air to the right, which forces the lighter balloon to the left.
A robot is placed on a 3 × 3 grid.
It starts at the top-left corner.
The robot can only move right (R) or down (D).
The robot must reach the bottom-right corner.
How many different successful paths are there?
6 different successful paths
For a list of five integers, the mode, median and mean are consecutive integers in increasing order.
What is the largest range possible for these five integers?
Largest range is 7.
Let the 5 integers be (x-1), (x-1), x, (x+1) and A as the mode is (x-1).
Total sum is 5x+5 as mean is (x+1). solving, A = x+6. The largest range is hence 7.
If a double-stranded DNA molecule contains 30% Adenine, what is the exact percentage of Cytosine?
20%
If A = 30%, then T must also be 30% (total 60%). That leaves 40% for G and C combined. Therefore, C is half of that (20%).
You have a sealed syringe filled with brown NO2 gas and colourless N2O4 gas at equilibrium:
2NO2 ⇌ N2O4
You push the plunger in. What happens to the colour of the gas after some time?
Turns a lighter brown
Pushing the plunger increases the pressure, favouring the forward reaction to produce fewer molecules, consuming some NO2 molecules to do so.
If you go back in time and accidentally prevent your own birth, you create a logical loop where you never existed to travel back in time at all. What is this famous idea called in theoretical physics?
The Grandfather Paradox
Preventing your grandparents from meeting means your parents are never born, and therefore you are never born to go back in time in the first place.
There are 7 doors in a row, all closed.
You toggle every door (open if closed, close if open).
Then you toggle every 2nd door, then every 3rd door, and so on up to the 7th door.
At the end, which doors remain open?
Doors 1 and 4