Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

 It is currently 18 Jul 2019, 20:50

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

## Events & Promotions

### Show Tags

19 Feb 2018, 23:24
1
00:00

Difficulty:

45% (medium)

Question Stats:

69% (02:05) correct 31% (02:13) wrong based on 58 sessions

### HideShow timer Statistics

Mr. Williams invested a total of $12,000 for a one-year period. Part of the money was invested at 5% simple interest, and the rest was invested at 12% simple interest. If he earned a total of$880 in interest for the year, how much of the money was invested at 12%?

(A) $1,920 (B)$4,000

(C) $4,800 (D)$7,200

(E) $8,000 _________________ Senior Manager Joined: 31 May 2017 Posts: 348 Re: Mr. Williams invested a total of$12,000 for a one-year period. Part  [#permalink]

### Show Tags

19 Feb 2018, 23:41
1
We can solve this question quickly by plugging in values and eliminating wrong answers straight away.

Step 1: Total interest rate accumulated is $880. Lets take a random split say$6000 each. Now if you calculate $6000 at 12% interest is$720 and at 5% is 300 which gives us $920. So part of amount invested at less than 12% is definitely less than$6000. Eliminate Option D and E. Actually we can eliminate option A without much calculation as well.

So we are left with option B and C.

Step 2:
Next lets take next highest value , $4800 ,which at 12% will yield$576 and rest of $7200 at 5% will yield 360.$576+$360 >$880.

So we are left with option B - $4000 - which @12% gives 480 and balance$8000 at 5% gives 400 - $480 +$400 = $880. Ans: B _________________ Please give kudos if it helps Resources | | | | | Senior SC Moderator Joined: 22 May 2016 Posts: 3077 Mr. Williams invested a total of$12,000 for a one-year period. Part  [#permalink]

### Show Tags

24 Feb 2018, 01:12
1
1
Bunuel wrote:
Mr. Williams invested a total of $12,000 for a one-year period. Part of the money was invested at 5% simple interest, and the rest was invested at 12% simple interest. If he earned a total of$880 in interest for the year, how much of the money was invested at 12%?

(A) $1,920 (B)$4,000

(C) $4,800 (D)$7,200

(E) $8,000 Try a weighted average approach, similar to that in mixture problems. Interest, as a percent, is like concentration. Let x = amount in dollars invested at 5% (below, equivalent to "weight") Let y = amount in dollars invested at 12% (below, equivalent to "weight") $$x + y = 12,000$$ $$x = 12,000 - y$$ $$(Rate_1)(Weight_1) + (R_2)(W_2)$$ = Total Interest $$.05x + .12y = 880$$ Substitute $$x = (12,000 - y)$$ $$.05(12,000 - y) + .12y = 880$$ $$600 - .05y + .12y = 880$$ $$.07y = 280$$ $$y = \frac{280}{.07}=\frac{28,000}{7}=4,000$$ Answer B _________________ SC Butler has resumed! Get two SC questions to practice, whose links you can find by date, here. Tell me, what is it you plan to do with your one wild and precious life? -- Mary Oliver Mr. Williams invested a total of$12,000 for a one-year period. Part   [#permalink] 24 Feb 2018, 01:12
Display posts from previous: Sort by

# Mr. Williams invested a total of \$12,000 for a one-year period. Part

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne