In mrs.Stevens class, there 3 boys for every 2 girls. If there 30 students in her 4th period class, how many are boys?
In mrs.Huber's 8th period class of 45 students, eight out of ten students received an A on the last test. How many got an A on the last test.
3.Lisa is painting a fence that 26 feet long and 7 feet tall. A gallon of paint will cover 350 square feet. Write and solve a proportion to determine how many gallons of paint Lisa will need.
Answers (3)
For every five students 3 of them are boys. If you divide 30 by 5 you see that there are six sets of 5 students. So take 6 x 3 to find out how many boys and 6 x 2 to find out how many girls. You end up with 18 boys and 12 girls.
Divide 45 by 10. you get 4.5. Take 4.5 times 8 to find out how many got A's 4.5 x 8 = 36
to find out how much paint you need to find the area of the fence. Multiply 26 x 7 to get the area of 182 square feet. 182 is roughly 1/2 gallon needed.
There are three boys for every two girls. 3+2=5, so divide 30 by 5. Of course the answer is 6, so multiply 6 by 3 and you have 18 boys, then 6 by 2 and you have 12 girls.
All you have to do here is set up the proportion like so:
8/10=x/45
Cross multiply and you will get a simple algebraic problem: 10x=360, divide 360 by 10 for x.
x=36 students received A's.
26/350=x/7
You will get the result
350x=182
x=0.52 gallons of paint.
3 i estimated 1 galoon of paint is enough because if you get the area in ftsquared it = 182 ftsquared and 1 gallon = 350 ftsquared