+0  
 
0
964
1
avatar

In Tina's Stamp collection, 70% of the stamps are Canadian and the rest are International. Tina has 500 more Canadian stamps than International stamps.How many stamps does she have

 Apr 2, 2016
edited by Guest  Apr 2, 2016
 #1
avatar
0

In Tina's Stamp collection, 70% of the stamps are Canadian and the rest are International. Tina has 500 more Canadian stamps than International stamps.How many stamps does she have.

 

Let Canadian stamps=C

Let International stamps=N

C=875     and        N=375

 

C - 500=N,  .70(N + C) =C

Solve the following system:
{C-500 = N |     (equation 1)
0.7 (C+N) = C |     (equation 2)
Express the system in standard form:
{-N+C = 500 |     (equation 1)
0.7 N-0.3 C = 0 |     (equation 2)
Add 0.7 × (equation 1) to equation 2:
{-N+C = 500 |     (equation 1)
0 N+0.4 C = 350 |     (equation 2)
Divide equation 2 by 0.4:
{-N+C = 500 |     (equation 1)
0. N+C = 875. |     (equation 2)
Subtract equation 2 from equation 1:
{-N+0 C = -375. |     (equation 1)
0 N+C = 875. |     (equation 2)
Multiply equation 1 by -1:
{N+0 C = 375. |     (equation 1)
0 N+C = 875. |     (equation 2)
Collect results:
Answer: |  N = 375        and             C=875
 

 Apr 2, 2016

0 Online Users