# how many coins

Helen Thomas

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Posts: 1759

posted 12 years ago

When Sarah received 10x coins, she then had 5y + 1 times as many coins as he had originally. In terms of x and y, how many coins did Sarah have originally?

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"God who creates and is nature is very difficult to understand, but he is not arbitrary or malicious." *OR* "God does not play dice." - Einstein

Maulin Vasavada

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Posts: 1873

Helen Thomas

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Posts: 1759

posted 12 years ago

Now that you laid it out neatly it doesn't look hard, does it ?

Thank you.

Question: Does 8x = 16 + 2x?

(1) -3x is greater than or equal to -9

(2) 2x is greater than or equal to 6

Which statement, if any or both is necessary to answer the question ?

II. similarly

If 4 students were added to a dance class, would the teacher be able to put her students evenly into a dance team(s) of 8?

(1) If 12 students were added, the teacher could put everyone in teams of 8 without any leftovers.

(2) The number of students in the class is currently not divisible by 8.

III.

The city council is creating an exploratory group for creating a new park. The city council consists of 20 representatives, 10 Republicans and 10 Democrats. The exploratory group will consist of 3 Republicans and 3 Democrats. How many different combinations are possible of city council members to make up the exploratory group?

[ September 15, 2004: Message edited by: Helen Thomas ]

Thank you.

Question: Does 8x = 16 + 2x?

(1) -3x is greater than or equal to -9

(2) 2x is greater than or equal to 6

Which statement, if any or both is necessary to answer the question ?

II. similarly

If 4 students were added to a dance class, would the teacher be able to put her students evenly into a dance team(s) of 8?

(1) If 12 students were added, the teacher could put everyone in teams of 8 without any leftovers.

(2) The number of students in the class is currently not divisible by 8.

III.

The city council is creating an exploratory group for creating a new park. The city council consists of 20 representatives, 10 Republicans and 10 Democrats. The exploratory group will consist of 3 Republicans and 3 Democrats. How many different combinations are possible of city council members to make up the exploratory group?

[ September 15, 2004: Message edited by: Helen Thomas ]

"God who creates and is nature is very difficult to understand, but he is not arbitrary or malicious." *OR* "God does not play dice." - Einstein

Arjun Shastry

Ranch Hand

Posts: 1899

1

posted 12 years ago

3 Rpublicans can be selected in 10C3 ways.

3 Democrats too can be selected in 10C3 ways.

Total numbers of combinations: 10C3 * 10C3 = (10*9*8/3*2*1)* (10*9*8/3*2*1)

= 14400

Now Mr. X is Republican and Mr Y is Democrat.and Mr X and Y are rivals.There are 6 chairs.How many arrangements are possible such that Mr. X and Mr Y are NEVER sitted adjacent?(X and Y are included in exploratory group )

[ September 16, 2004: Message edited by: Arjun Shastry ]

Originally posted by Helen Thomas:

III.

The city council is creating an exploratory group for creating a new park. The city council consists of 20 representatives, 10 Republicans and 10 Democrats. The exploratory group will consist of 3 Republicans and 3 Democrats. How many different combinations are possible of city council members to make up the exploratory group?

[ September 15, 2004: Message edited by: Helen Thomas ]

3 Rpublicans can be selected in 10C3 ways.

3 Democrats too can be selected in 10C3 ways.

Total numbers of combinations: 10C3 * 10C3 = (10*9*8/3*2*1)* (10*9*8/3*2*1)

= 14400

Now Mr. X is Republican and Mr Y is Democrat.and Mr X and Y are rivals.There are 6 chairs.How many arrangements are possible such that Mr. X and Mr Y are NEVER sitted adjacent?(X and Y are included in exploratory group )

[ September 16, 2004: Message edited by: Arjun Shastry ]

MH