Mental Math
What is 72 + 52 ?
74
Express 0.12 as a fraction in its lowest terms.
3/25
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0.12 = 12/100
HCF of 12 & 100 = 4
Therefore, 3/25
If the freezing point of mercury is -37 degrees and the boiling point is 198 degrees. What is the difference between them?
235 degrees
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190 - - 37 = 235
State the trigonometric ratios
Sine, cosine, tangent
State the three most commonly used measures of central tendency
Mean , Mode, and Median
If a book is priced at $45 and is on sale for 20% off, what is the sale price?
$36
A recipe requires 3 cups of flour for every 2 cups of sugar. If you want to make a larger batch using 12 cups of flour, how many cups of sugar will you need?
8 cups of sugar
Solve for x:
(x – 7)/3 = -12
x = -29
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(x – 7)/3 = -12
3*((x – 7)/3)= -12*3
x – 7 = -36
x – 7 + 7= -36 + 7
x = -29
What is the area of a triangle with a base of 10 cm and a height of 6 cm?
Area of a triangle =1/2×base×height
=1/2×10×6
=30 cm²
From the set below, best describe this type of mode:
{ 1 , 2, 2 ,3, 4, 4,6}
Bimodal - Two modes
How many minutes are there between 7:53 a.m. and 8:37 a.m the same day?
44 minutes
DOMLEC charges 75 cents per kWh for the first 60 kWh used on the energy bill and $1.25 per kWh for any additional energy used. Calculate your bill if you use 112 kWh for the month of October?
{USE OF CALCULATOR}
The total bill for October is $110
112 - 60 = 52
60 x .75 = $45 , 52 x $1.25 = $65
$45 + $65 = $110
The following angles total to 360 degrees.
170o , 2x + 50o , x -10o .
What is the value of x ?
x = 50
3x = 150 therefore x = 50
A circle has a radius of 4 cm. What is the circumference of the circle? (Use pi ≈3.14)
{ USE OF CALCULATOR}
2πr= 2×3.14×4
= 25.12 cm.
Write the formula for finding the mean in an ungrouped data set.
Mean = Efx /Ef or Efx/n
A triangle has angles measuring 450 and 750. What is the measure of the third angle?
600
Sarah spent 3/4 of her time at the park reading. She spent 2 hours reading, how much time (in minutes) did she spend in the park?
160 minutes
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120/3 = 40
40 x 4 = 160 minutes
Solve for x:
2(5x - 1) = 3(x + 11)
x = 5
WORK
2(5x - 1) = 3(x + 11)
10x - 2 = 3x + 33 [Distribute]
10x - 3x - 2 = 3x - 3x + 33
7x - 2 + 2 = 33 + 2
7x/7 = 35/7
x = 5
A 2.5m long ladder leans against the wall of a building. The base of the ladder is 1.5m away from the wall. What is the height of the wall?
{ USE OF CALCULATOR}
2m
In a survey of 10 households, the number of children was found to be {4, 1, 5, 4, 3, 7, 2, 3, 4, 1} . What is the median?
1, 1, 2, 3, 3, 4, 4, 4, 5, 7
median = (3+4)/2
= 3.5
A bag contains 3 red, 5 blue, and 2 green marbles. If one marble is drawn at random, what is the probability that it is blue?
The probability of drawing a blue marble is 1/2 or 50%.
A Nissan Frontier is advertised for sale at $84 000. It can also be bought on hire purchase by paying a deposit of 35% of the cost of the vehicle followed by 60 monthly payments of $1200 each. Calculate the hire purchase price. { Use of calculator}
29,400 + ( 60 x 1200)
= $101,400
Make x the subject of the formula
ax - c = 3x + b
x = (b + c) / (a - 3)
In a right-angled triangle, if one angle measures 300 and the length of the side opposite this angle is 5 cm, what is the length of the hypotenuse?
{ USE OF CALCULATOR}
10cm
The mean of these set of numbers: 43, 57, 63, 52 and x is 58. What is the value of x? {Use of calculator}
The value of x is 75
43, 57, 63 and 52 = 215
(215 + x)/5 = 58
5 x 58 = 290 - 215 = 75