Interhouse Mental Math Competition

Beginner 1

100

The result of 8 × 7.

56

200

The value of 120 ÷ 10

12

300

12x+3=63, solve for x

x =5

400

-76-88

-164

500

5³

125

Beginner 2

100

The sum of the first 5 positive integers

15

200

The value of (48 ÷ 6) + 7

15

300

The number you get when you double 37 and subtract 14.

60

400

The number whose square is 196

14

500

The value of 75% of 80 minus 12.

48

Intermediate 1

100

The value of 4² + 5²

41

200

The smallest integer that satisfies x > −2 and x ≤ 3.

x=-1

300

The value of (¾ × 48) − (⅓ × 18)

30

400

What's the name of this equation?

 a² + b² = c²

Pythagoras theorem 

500

The ratio of apples to oranges is 5 : 3. If there are 24 fruits altogether, the number of apples.

15 

Intermediate 2

100

If x + 7 = 3x − 5, the value of x

x=6

200

A right angle triangle with sides 3cm and 4cm, what is the length of the hypotenuse?

5cm

300

Given the points (4,2) and (-1,10), calculate the gradient of the line formed between them

-8/5

400

The simple interest on $200 at 5% per year for 2 years.

$20

500

The rate of interest if $60 is earned on $500 in 2 years at simple interest.

6%

Senior 1

100

A quadratic whose roots are alpha and beta

x²-(Alpha + beta)x + (Alpha)(beta) = 0

200

d/dx (cos(x))

-sin(x)

300

∫(4x³−6x+5)dx

x⁴-3x²+5x +c

400

The double angle formula for Cos2x

cos²x - sin²x

or 

1-2sin²x   or   2cos²x -1

500

tan(A+B) = ?

Tan(a) + Tan (b) / 1 - tan(a)tan(b)