Question on Converting Given Ratios into Proportions

Topic : Proportion Method

Question : Given ratios 25g : 30g and 40Kg : 48Kg Convert it into Proportions

Solution :
25g : 30 g = 25/30 = 5:6
40Kg : 48Kg = 40/48 = 5:6
So 25 : 30 = 40:48
Therefore, the ratios are in proportion
25:30 : : 40:48.

Question on Calculating Percentage of Saline Solution

Topic : Word Problem on Percentage

Question : How many ounces of pure water must added 50 ounces of 50% salt solution
To make saline solution that is 10% saline?

Solution :
15% of 50 + 0 % of x = 10% of (x+50)
0% means x ounces means pure water
7.5+0= 0.1x+5
2.5 = 0.1x
x=25.
Therefore 25 ounces of pure water must be added.

Word Problem on Work Done by Two People

Topic : Word problem

Question : Jethro can mow 5 lawnsin 4 hours while Otis can mow 5 lawns in 6 hours. How long will it take to mow 5 lawns together?

Solution :
Time taken by Jethro = 4 hrs
Jethro's one hour work = 1/4
Time taken by Otis = 6 hrs
Otis' one hour work = 1/6
Jethro's and Otis' work 1/4 + 1/6
= (1/4*3/3) + (1/6 *2/2)
= 3+2/12
= 5/12
Time taken together = 12/5 = 2.2hrs