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
To find where on the hill the canonball lands
So 0.15x = 2 + 0.12x - 0.002x^2
Taking the LHS expression to the right and rearranging we have -0.002x^2 + 0.12x -
0.15x + 2 = 0.
So we have -0.002x^2 - 0.03x + 2 = 0
I'll multiply through by -1 so we have
0.002x^2 + 0.03x -2 = 0.
This is a quadratic eqn with two solutions x1 = 25 and x2 = -40 since x cannot be negative x = 25. The second solution y = 0.15 * 25 = 3.75
Answer:
B. 300
Step-by-step explanation:
Final figure volume = big cuboid volume - small cuboid volume
Volume of a cuboid = height x width x length
Final figure = (6 x 6 x 15) - (4 x 4 x 15)
Final figure = 540 - 240
Final figure = 300mm^2
The answer is...
1. B
2. B
3. B
4.C
5.C
7.5. 10.5*5 and divide that by 7