Three people share a sum of money. The 1st person receives 25 of the sum and the 2nd person receives 12. What fraction of the money does the 3rd person receive?
Add fractions with unlike denominators by transforming the fractions so that they have like denominators
First, list down the values stated in the problem
1st person
=
25
2nd person
=
12
Use cross method to add the two fractions.
First, multiply the two denominators. Use the product as a denominator for a new fraction.
25+12
=
☐5×2
=
☐10
To get the numerator, cross multiply the given addition problem and add the products.
25+12
=
(2×2)+(5×1)10
=
4+510
=
910
Finally, subtract this fraction from 1. 1 represents the whole sum of money
1−910
=
1010−910
Subtract the numerators
=
110
Keep the same denominator
The 3rd person gets 110 of the money.
110
Question 2 of 4
2. Question
A rain tank is three fifths full. Heavy rain over a period of 3 nights filled it with one tenths of water each night. What fraction of the tank’s capacity is filled after the 3 nights of rainfall?
Add fractions with unlike denominators by transforming the fractions so that they have like denominators
First, list down the values stated in the problem
Starting amount of water
=
35
Additional amount of water
=
3×110=31×110=310
Add the two values to get the total amount of water after 3 days
Since 10 is a multiple of 5, it is the LCD of 5 and 10
35+310
=
3×25×2+310
Multiply 2 to 5 so it becomes 10
=
610+310
=
910
Keep the same denominator
910
Question 3 of 4
3. Question
A concrete truck contains a concrete mixture that consists of 14 cement, 13 sand, 16 water and the rest is gravel. What fraction of the mixture is gravel?
Since we are looking for the fraction that Eddie ate, the numerator must be the no. of slices he ate while the denominator must be the total no. of slices
no.ofslicesheatetotalno.ofslices
=
516
Eddie ate 516 of the pizza he ordered.
(ii) Find the fraction of pizza that remains.
Simply subtract the fraction that Eddie ate from 1. Here, 1 represents the total pizza that he ordered.