Sign Up!
Login
Welcome to Test-paper.info
Monday, November 20 2017 @ 05:59 AM CST
 Forum Index >  Test Paper Related >  Primary 6 Matters
 Maths problem sum P6 (pls help)
   |  Printable Version
By: richardli (offline)  Sunday, July 08 2012 @ 01:20 AM CDT (Read 847 times)  
richardli

At the start of a game, Alice had 75% as many cards as Bob.
Bob had 30% as many cards as Calvin. During the first round,
Alice lost1/3 of her cards to Bob. During the second round, Bob
lost 30% of his card to Calvin. At the end of the game, Calvin had
462 more cards than Alice.

a) how many cards did Bob have at first?
b)what was the percentage increase in Calvin's number of cards
at the end of the game?

Forum Newbie
Newbie

Registered: 12/31/06
Posts: 10

Profile Email    
   
By: echeewh (offline)  Sunday, July 08 2012 @ 09:44 PM CDT  
echeewh

Hey Richard,

Following pls find my worked solution:

A : B : C

3 : 4 -- (1)
3 : 10 -- (2)

<Apply Repeated / Common Identity concept> means B must have same number of units in these 2 ratios.

(1)x3: (2)x4:

9 : 12 : 40

<Round 1>
A lost (1/3) of her cards to B.

A: 9 - 3 = 6u
B: 12 + 3 = 15u
C: 40u

<Round 2>
B lost 30% (3/10) of his cards to C.

A: 6u
B: 15u - [(3/10) x 15]u = 15u - (9/2)u = (21/2)u
C: 40u + (9/2)u = (89/2)u

Given that C - A = 462, we have ...

(89/2)u - 6u --> 462
89u - 12u --> 462 x 2
77u --> 924
1u --> 12

(a) B (at first) = 12u --> 12 x 12 = 144
(b) % inc in C's cards at end of game

(89/2)u - 40u = (9/2)u
(9/2)u --> (9/2) x 12 = 54
% inc = [54 / (40 x 12)] x 100 = (54/480) x 100
= 11.25%

==================================

Trust this helps.

Do let me know again if there's any clarification.

Cheers,
Edward

Forum Active Member
Active Member

Registered: 04/21/11
Posts: 627

Profile Email    
   


 All times are CST. The time is now 05:59 am.
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