Question 479135
1.The units digit of a two-digit number is 3 more than its tens digit. If the number is divided by the sum of its digit's, the quotient is 4 and the remainder is 3. Find the number.

y-unit digit
x ten's digit
y=x+3........1
(10x+y+3/(x+y)) =4
10x+y+3=4(x+y)
10x+y+3=4x+4y
6x-3y=-3
/3
2x-y=-1
substitute y 
2x-x-3=-1
x=2
plug x in (1)
y=2+3
y=5
Number = 25



.Paul's investment is 10 000 less than thrice his sister's investment. If their total inestment amounts to 150 000, how much is Paul's investent?

Sister = x
Paul = y 
y=3x-10000......1
x+y= 150000......2
substitute y in (2)
3x-10000+x=150000
4x=160000
x=$40000---- sister's investment
Paul's investment = 3x-10000===> 120000-10000=$ 110,000



3.Working together, Alleli and gemma can finnish their math  project in 5 hours. Alleli can finish it alone twice as much time as gemma can do the job. How long will it take gemme to finnish the project alone?

Gemma takes x hours
so she does 1/x  of job in 1 hour
Alleli takes 2x hours
so she does 1/2x of the job in 1 hour

Together they do 1/5 of the job in 1 hour

1/x + 1/2x= 1/5
LCD = 10x multiply equation by the LCD
10+5=2x
2x=15
x= 7.5 hours time taken by Gemma alone
m.ananth@hotmail.ca