Sign Up!
Login
Welcome to Test-paper.info
Sunday, August 20 2017 @ 09:53 PM CDT
 Forum Index >  Test Paper Related >  Primary 3 Matters
 P5 Maths Problem
   |  Printable Version
By: Aliah (offline)  Wednesday, October 13 2010 @ 05:43 AM CDT (Read 1711 times)  
Aliah

Can anyone please help me to solve these maths problems?

1) Andy and Benny have 80 books altogether. Benny and Colin have 70 books altogether.
Andy and Colin have 90 books altogether. How many books does each of them have?



2) A box contains 36 similar mirrors. The total mass of the box together with 3/4 of the mirrors
is 11.25kg lighter than that of the box with all the mirrors. The mass of each mirror is 5/7 of
mass of the box. What is the total mass of the box with the 36 mirrors?



3) A bookshop owner bought an equal number of files and exercise books. She spent 3/5 of her
money on the files and 1/4 of the remainder on exercise books. She could buy another 1200
exercise books with the rest of her money.

a) How many exercise books did she buy at first?

b) If each file cost $2.50 more than each exercise book, what was the cost of an exercise book?



Thank You.

Forum Newbie
Newbie


Registered: 10/13/10
Posts: 3

Profile Email    
   
By: suz855 (offline)  Thursday, October 14 2010 @ 05:53 AM CDT  
suz855

Q1. Given A+B=80
B+C=70
A+C=90

If we sum them altogether, we'll have 2 x (A+B+C) = 240, therefore, A+B+C = 120
Problem will then be solved, since A+B=80, therefore C = 40 & so on.....

Q2. Given the total mirrors were 36, therefore 1/4 of them will be 9 mirrors.

Since the mass of the box is constant, the 11.25kg will be the mass of the 9 mirrors, we can then find the mass of 1 mirror

(1mirror) --> 11.25 divide by 9 = 1.25kg
Given mass of 1 mirror is 5/7 the mass of the box, mass of box shall be 1.25 divided by 5 multiply by 7 which is 1.75kg.
Puting everything together 1.75kg + 36 x 1.25kg = 46.75kg

Q3. [ | ][ | ][ | ][ | ][ | ]
<-----------> <---->
files left

(left)--> 3u = 1200 books, therefore number of files equal to number of books which will be 400
Since given each file cost 2.50 more than a book, 400 files shall cost 400 x 2.50 = $1000 more

5u --> 1000, therefore, 1u = 200

cost of a book = 200 divide 400 = $0.5

Big Grin

Forum Junior
Junior


Registered: 12/31/06
Posts: 16

Profile Email    
   
By: Aliah (offline)  Friday, October 15 2010 @ 07:49 AM CDT  
Aliah

Quote by: suz855

Q1. Given A+B=80
B+C=70
A+C=90

If we sum them altogether, we'll have 2 x (A+B+C) = 240, therefore, A+B+C = 120
Problem will then be solved, since A+B=80, therefore C = 40 & so on.....

Q2. Given the total mirrors were 36, therefore 1/4 of them will be 9 mirrors.

Since the mass of the box is constant, the 11.25kg will be the mass of the 9 mirrors, we can then find the mass of 1 mirror

(1mirror) --> 11.25 divide by 9 = 1.25kg
Given mass of 1 mirror is 5/7 the mass of the box, mass of box shall be 1.25 divided by 5 multiply by 7 which is 1.75kg.
Puting everything together 1.75kg + 36 x 1.25kg = 46.75kg

Q3. [ | ][ | ][ | ][ | ][ | ]
<-----------> <---->
files left

(left)--> 3u = 1200 books, therefore number of files equal to number of books which will be 400
Since given each file cost 2.50 more than a book, 400 files shall cost 400 x 2.50 = $1000 more

5u --> 1000, therefore, 1u = 200

cost of a book = 200 divide 400 = $0.5

Big Grin




Thanks Suz855 for the solutions.

Forum Newbie
Newbie

Registered: 10/13/10
Posts: 3

Profile Email    
   


 All times are CDT. The time is now 09:53 pm.
Normal Topic Normal Topic
Locked Topic Locked Topic
Sticky Topic Sticky Topic
New Post New Post
Sticky Topic w/ New Post Sticky Topic w/ New Post
Locked Topic w/ New Post Locked Topic w/ New Post
View Anonymous Posts 
Able to Post 
HTML Allowed 
Censored Content