SOLUTION: In a class, the ratio of right-handed to left-handed students is 7:2. The total number of students is 36. If none of the students is ambidextrous, what is the number of left-handed

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: In a class, the ratio of right-handed to left-handed students is 7:2. The total number of students is 36. If none of the students is ambidextrous, what is the number of left-handed      Log On


   

Question 1176617: In a class, the ratio of right-handed to left-handed students is 7:2. The total number of students is 36. If none of the students is ambidextrous, what is the number of left-handed students in the class?
Found 2 solutions by math_tutor2020, ewatrrr:
Answer by math_tutor2020(3817) About Me  (Show Source):
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The ratio of right-handed to left-handed is 7:2
This could mean we have 7 right-handed people and 2 left-handed people. This gives 7+2 = 9 total students in the class.

However, we're told that we actually have 36 total students. The jump from 9 to 36 is "times 4", since 36/9 = 4.

So we must multiply every value of 7:2 by 4 to get
7*4 = 28
2*4 = 8

Then note how 28+8 = 36 and how the ratio 28:8 reduces to 7:2 when you divide both parts by 4. Put another way, 7:2 turns into 28:8 when you multiply both parts by 4.

The ratio 28:8 means we have 28 right-handed people and 8 left-handed people.

Answer: 8

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!

Hi
the ratio of right-handed to left-handed students is 7:2.
(More what one would expect)
Using constant of Proportionality:

 7c + 2c = 36
    9c = 36 
     c = 4
           8 the number of lefthanded in class.

 28 + 8 = 36  checks.
Wish You the Best in your Studies.