The ratio of roses to tulips is 2 to 5. How many roses are there in a bouquet of 28 flowers.

Question

I'm having a really hard time with this question.

Answer 1

Or just divide 2 ( the number of roses in the ratio) by 7 (the total number of flowers in the ratio) and you get approximately 28.5%.  Multiply the 28 total by .285 and you get 7.98, which would be 8 since you are talking about whole flowers.

Answer 2

ratio of roses to tulips is 2 to 5

2x+5x=28

7x=28

x=28/7

x=4

4*2=8 roses (4*5=20 tulips)

or...

 

roses     tulips

2           5

4           10

6           15

8           20     (8+20=28 and 8/20=2/5)

 

Answer 3

OK then. You have two sets of flowers. Tulips, and let's say you have T of those. And roses, where you have 28-T. (Because the total of flowers is 28.) The ratio of roses to tulips is 2 to 5. This means

 

(28 - T) / T = 2/5

 

Cross-multiply. No doubt you've seen that phrase by now. :-)

 

5 (28 - T) = 2T

140 - 5T = 2T

140 = 7T

20 = T

 

You have 20 tulips. That leaves you eight roses. You're going to have to practice a few of these kinds of problems to build up your speed in time for a test. :-)