The ratio of sunny days to rainy days in Vancouver is 3:5. How many sunny days and how many rainy days are in a year? Use proportions

Question

Use proportions and the answer I got is 146 sunny days and 219 rainy days but that's incorrect

Answer 1

Let's call the number of sunny days s and the number of rainy days r.

 

We know the ratio is 3 sunny days for every 5 rainy. An equation for this is:

 

s/r = 3/5

 

Let's simplify that to:

 

s = 3/5 r

 

We also that the total number of days is 365:

 

s + r = 365

 

Let's put (3/5 r) in for s and simplify:

 

(3/5 r) + r = 365

8/5 r = 365

r = 365 (5/8) = 228

 

Now we can solve for s:

 

s = 3/5 (228) = 137

 

We can double check by adding s and r: 228 + 137 = 365

 

Your problem was seeing the ratio 3:5 and multiplying it right away by 365. The ratio of rainy days to total days is 5:8 (not 3:5), and the ratio of sunny days to total days is 3:8 (not 2:5).