Given that,
y varies directly with x and y = 10 when x = 20.
To find,
The value of y when x = 15.
Solution,

Put x = 20 and y = 10

Put k = 1/2 and x = 15 to find the value of y.

So, the value of y is 7.5
Answer:
56
Step-by-step explanation:
Basically you want to find out what is 70% of 80.
first you have to set up your problem
= 
the first fraction would be the percent (70) over 100. (you always use 100)
The fraction to the left would be n over 80. the denominator (the number on the bottom) would be the whole amount. n would be the unknown number
To solve you would use the butterfly method. 80 x 70 and 100 x n. 80 x 70 is 5600 and 100 x n is 100n.
The final step is dividing. 5600 divided by 100 giving you 56
Answer:
134 degrees.
Step-by-step explanation:
This is a simple one.
The arc RS subtends an angle of 67 degrees on the circumference,
So the measure of the arc RS is 2 * 67 = 134 degrees.
Answer:
36 pages per day on average
Step-by-step explanation:
Calculate the average.
3 * 28 (The first 3 days of the week where Mike reads 28 pages per day) = 84
4 * 42 (The next 4 days where Mike reads 42 pages per day ) = 168
168 + 84 = 252
To find the average using this total, divide it by the total amount of days of reading (seven days in this problem).
252 / 7 = 36
I used to hate fractions. But in time, you learn to love them. This is because there's a big difference between fractions and decimals, even though when you divide the actual fraction it comes out to a decimal. Decimals go on and on sometimes, and it would be impossible to write out all those numbers, especially when taking a timed test, for example. Fractions, in this case, would be much more useful (as long as you know how to use them to your advantage). Fractions are basically all those decimal numbers wrapped up into a single, simple division. It makes the outcome of your answer much more accurate than if you estimate every decimal you get throughout a math problem. The more you estimate throughout the problem-solving process, the less accurate your final answer will be. Hence why teachers will usually tell you to estimate when you're putting down the final answer. Fractions are complex at times, so it may be easier to use them in decimal form for certain situations (especially if the decimal form is short and sweet). A world without fractions will result in many, many inaccurate situations involving mathematical knowledge.