Problema Solution
The amount of rice cake mix to be used varies directly with the number of people who partakes of this food. Suppose that it takes 7 cups of mix to serve 10 people.
a.) Write the function expressing the number of cups of cake mix in relation to the number of people.
b.) How many cups of cake mix must be prepared for 50 people?
c.) About how many people can be served with 12 cups of cake mix?
These are my unsure answers:
For the letter b, i've tried solving it like this:
= 7/10=x/50
= 10x/10=350/10
= x=35
For letter c, I tried this:
= 12/7=x/10
= 7x/7=120/7
= x=17.14
So basically i don't understand letter a.
Answer provided by our tutors
a.) Write the function expressing the number of cups of cake mix in relation to the number of people.
y = the number of people served
x = the number of cups of cake
y : x = 10 : 7
y/x = 10/7 multiply both sides by x
y = (10/7)x
b.) How many cups of cake mix must be prepared for 50 people?
7/10=x/50
10x = 7*50
10x/10=350/10
x=35 cups of cake mix
Another way to solve it, is to use the equation from a) y = (10/7)x, where y = 50 people
50 = (10/7)x
x = (7/10)*50
x = 35 cups of cake mix
c.) About how many people can be served with 12 cups of cake mix?
use the equation from a) y = (10/7)x, where x = 12 cups of cake mix
y = (10/7)*12
y = 120/7
y = 17 people
Or we can solve it as you did: if x represent the number of people then we can write
7 : 10 = 12 : x
x = (12*10)/7
x = 17.14 or 17 people (we can not serve fractions of people).