9 Specialist Unit 1 Revision

Number Systems

100

111 in binary is equal to what number in decimal?

7

200

4230 in octal is equal to what number in decimal?

2200

300

110111010101 in binary is equal to what number in decimal

3541

400

195 in decimal is equal to what number in binary

11000011

500

61 in decimal is equivalent to what number in octal

75

Recurring Decimals

100

Express 0.71 recurring as a common fraction

71/99

200

Express 0.629 as a common fraction

629/999

300

Express 0.14 as a common fraction

13/90

400

Express 1.528 as a common fraction

1 & 523/990

500

Express 0.6177 as a common fraction

6171/9990 OR 2057/3330

GCD

100

Find the GCD of 96 and 72

(96, 72) = 24

200

Find (256, 512)

(256, 512) = 256

300

Find (41361, 551480)

(41361, 551480) = 13787

400

Find (59619, 675682)

(59619, 675682) = 19873

500

Find (645450, 258180)

(645450, 258180) = 129090

LCM

100

Find the LCM of 24 and 12

24

200

Find [20, 24]

[20, 24] = 120

300

Find [240,300]

[240,300] = 1200

400

Find [746, 250]

[746, 250] = 93250

500

Find [8508, 9728] = 

[8508, 9728] = 20691456

Pot Luck

100

Find the LCM of 150 and 900

The LCM of 150 and 900 is 900

200

What is (56,60) equal to?

(56,60) = 4

300

Express 0.24 as a common fraction

22/90 or 11/45

400

We want to create groups of students with the same numbers of students from each year level.  If I have 120 year 7 students, 90 year 8 students and 135 year 9 students, how many groups can I create?

(90,120,135) = 15

So 15 groups can be created with an equal number of students from each year level.

500

If Train A departs every 7 minutes, Train B departs every 4 minutes, and Train C departs every 15 minutes, how long until they all depart at the same time if they last departed at the same time 5 minutes ago?

[4,7,14] = 56 so the next time all three trains depart together is 56-5 = 51 minutes from now