Jump to content
Urch Forums

how to solve this?


weirdo

Recommended Posts

If the length and width of a rectangular diagram 12 inches by 8 inches are to be reduced by

the same percent so that the diagram will exactly fit into a rectangular space 4.5 inches by 3

inches, by what percent should the dimensions be reduced?

(A) 25%

(B) 37.5%

© 62.5%

(D) 75%

(E) 87.5%

 

In a certain community, 39,285 more apartments were converted to condominiums and sold in

1981 than in 1980. If this was a 30 percent increase, how many apartments were converted

and sold in 1981?

(A) 11,786

(B) 51,070

© 91,665

(D) 130,950

(E) 170,235

 

i got these from korean pdf..the second one says asnwer is e, but i got D..and i am not been able to solve first one quickly, answer is c for first

 

thanks

Link to comment
Share on other sites

for the the first Q I used POE; since the lenght is reduced from 12 to 4.5 and breadth from 8 to 3 inches; then its been reduced a little more than 50%

 

but i would like to know how to solve it mathematically!

 

for the second one

 

x * 30% = 39,285

soving for x you get 130,950

Link to comment
Share on other sites

The answers for both questions are correct.

  • If the length and width of a rectangular diagram 12 inches by 8 inches are to be reduced by the same percent so that the diagram will exactly fit into a rectangular space 4.5 inches by 3 inches, by what percent should the dimensions be reduced?
    (A) 25%
    (B) 37.5%
    © 62.5%
    (D) 75%
    (E) 87.5%

We have increase in length=12-4.5 = 7.5

% increased in length=(7.5 / 12) X 100 %

=62.5 %

Increase in breadth= 8 – 3 =5

% increased in breadth = (5/8) X 100%

=62.5 %

2 )In a certain community, 39,285 more apartments were converted to condominiums and sold in 1981 than in 1980. If this was a 30 percent increase, how many apartments were converted and sold in 1981?

(A) 11,786

(B) 51,070

© 91,665

(D) 130,950

(E) 170,235

say in 1980 “x” apartments were sold.

We have Increase in 1981 = 39285

(30/100) x = 39285

=>x=130950

so in 1981 no. of apartments sold= no. sold in 1980 + increase in 1981

= x + 39285

=170235

I hope the solution is clear…

Link to comment
Share on other sites

The answers for both questions are correct.

say in 1980 “x” apartments were sold.

We have Increase in 1981 = 39285

(30/100) x = 39285

=>x=130950

so in 1981 no. of apartments sold= no. sold in 1980 + increase in 1981

= x + 39285

=170235

I hope the solution is clear…

 

Dammit! :doh:

 

Thanks Zephyr.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...