Maths Tips

Question 1

When dividing or multiplying by a negative

Answer 1

Flip the inequality

Question 2

Finding the mean of new members

Answer 2

Set up two equations
Subtract original mean from new mean
Divide by number of additions

Question 3

Rearranging

Answer 3

Don’t expand

Question 4

Simultaneous equations

Answer 4

Try multiplying them up

Question 5

Remember, if things are proportional you can keep k as

Answer 5

1

Question 6

Remember scale factors

Answer 6

Length to volume is cubed

Question 7

Let original

Answer 7

Original x 1.(profit) = price

Question 8

Watch out for diameter

Answer 8

!!!

Question 9

Always

Answer 9

Could be none of them

Question 11

Binary fission

Answer 11

Not mitosis!
Genetically identical (barring mutations)
Chromosome replication in cytoplasm

Question 12

Gametogenesis

Answer 12

Can be mitosis in plants

Observe n value

Question 13

Fertilisation

Answer 13

Is not mitosis

Question 14

Adult stem cells

Answer 14

Contain the same genes as somatic cells

Question 15

As soon as you figure out x

Answer 15

Sub it in

Question 16

Quadratic sequences

Answer 16

find second difference - half it for n2

Find difference between first sequence and the quadratic sequence multiplied by the second difference for integer term

Question 17

Requirements for cells near the tip of the plant shoot to grow differently

Answer 17

Sufficient oxygen and glucose

Uneven distribution of plant hormone

Question 18

Mutations

Answer 18

Can occur in gametes

Question 19

Processes involved in dolly

Answer 19

Mitosis, meiosis and differentiations

Not genetic engineering

Question 20

If given two coordinates

Answer 20

Sub in for simultaneous equations

Question 21

How many numbers of copies of DNA sequence found

Answer 21

In human cells: 2
In bacteria cells: 1
In proteins: 0

Question 22

X-acid and y-axis

Answer 22

Must be correct

Question 23

Number of gas bubbles released per minute

Answer 23

Is not directly proportional

Question 24

When u have h and r

Answer 24

Look for relationships

Is h 2r?

Question 25

Dividing a number by a surd

Answer 25

Turn the number into a surd

Question 26

If you see ‘less than’ or ‘greater than’

Answer 26

Set up an inequality

Question 27

If it’s early on and ur really stuck with a triangle

Answer 27

Assume it’s right angled and use trig/Pythagorean’s

Question 28

When you’ve found an algebraic gradient and Ur solving it in an inequality

Answer 28

Ignore the fact it’s a fraction and solve both lines as an inequality for the limits

Question 29

Watch out for the inequality

Answer 29

If your answer has to be greater than/less than (NOT equal to) bear this is mind when choosing the smallest/largest possible value of something

Question 30

Probability trees

Answer 30

Remember, are they replaced? Do they probabilities change each time?

Question 31

Clock Q method

Answer 31

1) figure out what fraction the hour hand has made it though the hour, call this θ
2) θ x 30 = fraction
3) add this to the angle between the minute hand and the UB of the hour hand

Question 32

If you have a surd over a fraction

Answer 32

Think about if there is something you can factor out of the top to show as a multiple

Question 33

Finding bearings of legs of runs

Answer 33

1) The exterior is the angle by which the bearing changes each leg
2) find number of turns, multiply by exterior angle and subtract this from the first value
3) if you get a negative number, this is the anti-clockwise bearing

Question 34

Change in y/ change in x

Answer 34

If you have a variable, don’t forget to put things in brackets

Question 35

Bearings

Answer 35

Make sure you’re going from north

Question 36

4 x 4

Answer 36

Is 16 not 8 u moron

Question 37

If given a rhombus diagonals

Answer 37

Can assume half-distances to set up right hand triangles

Question 38

If it’s already factorised?

Answer 38

Don’t immediately expand

Is there anything u can cancel

Question 39

If the numbers are looking tricky

Answer 39

Look! Can you cancel?

Question 40

Remember the difference between Co-ordinates and distance

Answer 40

Yep

Question 41

Looking for similar shapes

Answer 41

Use θ1 and θ2

Question 42

Remember total surface area

Answer 42

Have to use width, depth and height

Question 43

If you have a triangle and area

Answer 43

Watch out! You might not have to make it into two right angled triangles if you already have the perpendicular height anyway

Question 44

If there’s a ratio in the question

Answer 44

Make an equation and then make back into a ratio

Question 45

Probability

Answer 45

Is it quicker to find the probability of the event NOT happening?

E.g. 1-P(X)