Answer:
12/5hours=2.4 hours
Step-by-step explanation:
Sam:6hours
Tom:4hours
This is a rate problem
Sam's rate is one job completed in 6 hours which is 1/6
Tom's rate is one job completed in 4 hours which is 1/4
Together, they could complete 1/4+1/6 of the job in y hours
We are trying to find the rate at which Sam and Tom could complete the job together, or one job in x days, for a rate of 1/y
1/4+1/6=1/y
The least common denominator is 12y
Multiplying through by the LCD which gives:
12y(1/4)+ 12y (1/6)= 12y (1/y)
3y + 2y=12
5y = 12
y=12/5 hours=2.4hours
Therefore it will take 12/5 hours or 2.4 hours to complete the job if they work together
Answer:
10 hours
Step-by-step explanation:
320 = 30x + 20
300 = 30x
x = 10
Answer:

Step-by-step explanation:
see the attached figure with letters to better understand the problem
Let
a ----> the height of rectangle in mm
b ---> the base of rectangle in mm
step 1
Find the base of rectangle
----> by segment addition postulate
substitute

step 2
Find the height of rectangle
---> by segment addition postulate
substitute the given values

Find the length sides CG
Applying the Pythagorean Theorem

substitute the given values



simplify

therefore

step 3
Find the area of rectangle

we have


substitute

Let length of rectangle=x and width be y
.`. area=x*y
now new length=x+12x/10=22x/10
width=y-y/5=4y/5
now .....
new area=new length-new width=22x/10*4y/5
new area=88xy/50
91.5 is the perimeter. It's just 5a.