The ratio is 4:3:1
let the ratio be 4x:3x:x
according to the question,4x+3x+x=40
8x=40
x=5
therefore amount of gravel=x*4=5*4=20
amount of sand=5*3=15
amount of cement=5*1=5
Using equations to solve the word problem, Katherine's age is 8 years
<h3>Word Problem</h3>
Word problem are often mathematical problem that are represented in words and sometimes can be solved using an equation.
To solve this problem, we have to represent the problem using mathematical equations;
Let;
Katherine's age = x²
Alexandra = 5(x + 1)
Sum of their age = 109
5(x + 1) + x² = 109
5x + 5 + x² = 109
x² + 5x - 104 = 0
Solving for the equation; x = 8
Katherine's age is 8
Learn more on word problem here;
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Answer:
Cross Sectional
Step-by-step explanation:
A cross sectional is one in which an association is developed between a risk factor or an outcome.
In the given question the device is used to record the viewing habits of about 2500 households, and the data collected today will be used to determine the proportion of households tuned to a particular news program. There will be risk factor in today's research with the future developed program which will the outcome.
For example there are 20 students in my class who cannot write. So I develop a program to help them write. But the next year there may not be any student who would require such help.So there's a risk factor associated with the outcome.
Cross sectional results are recorded in a two ways table showing do's and don'ts.
Sand to cement
7:3
210:x
ask yourself what number is needed to multiply by 7 to get 210 ( so you'd divide 210 by 7 which is 30). Multiply the other side by thirty as well to get the value of x
3*30 which is 90
Step-by-step explanation:
megan owes the bank 14 dollars, but she then deposits 6 dollars. she now owes the bank 8 dollars
