Please i need help with high school mathematics

A

Agbaje Adeniyi

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1. A is 3yrs older than B And 2 and half times older than C, if the sum of their ages is 69, how old are they?
2. A car travels from town P to Q at an average speed of 75km/hr, the average speed of the car on the return journey Was 65km/hr, If the total time taken for the journey was 10hours, What is the distance between town P and town Q?
 
Agbaje Adeniyi said:
1. A is 3yrs older than B And 2 and half times older than C, if the sum of their ages is 69, how old are they?
2. A car travels from town P to Q at an average speed of 75km/hr, the average speed of the car on the return journey Was 65km/hr, If the total time taken for the journey was 10hours, What is the distance between town P and town Q?
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Please follow the rules of posting in this forum, as enunciated at:

READ BEFORE POSTING

Please share your work/thoughts about this assignment.

Since posted these problems are in pre-algebra section - I assume you do not know algebra yet.

Start with assuming that all the ages are integers.

If you cannot use algebra - you have to apply guess-and-correct method.
 
Agbaje Adeniyi said:
1. A is 3yrs older than B And 2 and half times older than C, if the sum of their ages is 69, how old are they?
Click to expand...
Let A = the age of person named A
Let B = the age of person named B
Let C = the age of person named C
A is 3yrs older than B
is means =
3yrs older than B means B+3
So A = B+3

2 and half times older than C means 2.5*C
A is 2 and half times older than C becomes A =2.5*C

Given that A+B+C=69

Continue from here.
 
Last edited:
Jomo said:
A is 3yrs older than B
is means =
3yrs older than B means B+3
So A = B+3

2 and half times older than C means 2.5*C
A is 2 and half times older than C becomes A =2.5*C

Given that A+B+C=69

Continue from here.
Click to expand...
Jomo,

A, B & C are the names of people - not AGES.

Back to the corner for 69 minutes!!!
 
Jomo said:
You are correct. I will fix that right now.
Let A = the age of person named A
Let B = the age of person named B
Let C = the age of person named C
Click to expand...
Then all your equations change! (A becomes A, and so forth)
 
Agbaje Adeniyi said:
1. A is 3yrs older than B And 2 and half times older than C, if the sum of their ages is 69, how old are they?
Click to expand...
B= A- 3. A- C= (5/2)C so A= (5/2)C C= (2/7)C. A+ A- 3+ (2/5)A= 69. (12/7)A= 72. A= 7(72/12
Jomo said:
Let A = the age of person named A
Let B = the age of person named B
Let C = the age of person named C
A is 3yrs older than B
is means =
3yrs older than B means B+3
So A = B+3

2 and half times older than C means 2.5*C
A is 2 and half times older than C becomes A =2.5*C
Click to expand...
No, it doen't- although that is probably what is meant.
A= 2.5C would be "A is 2 and a half times as old as C".
"A is 2 and a half times older than C" means that A= C+ 2.5 C but that gives fractional ages. The question is probably written wrong and your interpretation, though grammatically incorrect, is probably the right one!

Given that A+B+C=69

Continue from here.
Click to expand...

)=
2. A car travels from town P to Q at an average speed of 75km/hr, the average speed of the car on the return journey Was 65km/hr, If the total time taken for the journey was 10hours, What is the distance between town P and town Q?
[/QUOTE]
 
HallsofIvy said:
B= A- 3. A- C= (5/2)C so A= (5/2)C C= (2/7)C. A+ A- 3+ (2/5)A= 69. (12/7)A= 72. A= 7(72/12

No, it doen't- although that is probably what is meant.
A= 2.5C would be "A is 2 and a half times as old as C".
"A is 2 and a half times older than C" means that A= C+ 2.5 C but that gives fractional ages. The question is probably written wrong and your interpretation, though grammatically incorrect, is probably the right one!



)=
2. A car travels from town P to Q at an average speed of 75km/hr, the average speed of the car on the return journey Was 65km/hr, If the total time taken for the journey was 10hours, What is the distance between town P and town Q?
Click to expand...
JOMO,

Back to the corner ...... again.....
 
Agbaje Adeniyi said:
1. A is 3yrs older than B And 2 and half > > > times older than < < < C,
if the sum of their ages is 69, how old are they?
Click to expand...

HallsofIvy already commented about this phrase. This phrase should not be used in writing.

It's mixing two ideas: multiplication and addition. But, it intends multiplication only.
The "times as old" phrase does make sense for one of the alternates.
 
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