Categories
Ratio Proportion Smart Math

[Smart Math] Ratio Proportion Problem 37

Here’s and example of a SMART MATH problem for RATIO PROPORTION.

Ratio Proportion

Problem

What sum of money is divided between A, B and C; if B and C together get $100 and C and A together get $150 and A gets twice as much as B.

  1. $200
  2. $250
  3. $300
  4. $350
  5. $400

The Usual Method

[contentblock id=google-adsense-post]

Let A, B and C individually get $’1’, $’2’ and $’3’.

Hence,

b+c=100                                …… Eq. 1

c+a=150 and             …… Eq. 2

a=2b                                      …… Eq. 3

\therefore a+b+2c=250

\therefore 2b+b+2c=250

\therefore 3b+2c=250

=b+(2b+2c)=250

2b+2c=200                            ……From Eq. 1

\therefore b+200=250

from Eq. 1,

\therefore a+b+c=100+50+50=200 ……From Eq. 2

Hence total sum = $200

(Ans: 1)

Estimated Time to arrive at the answer = 75 seconds.

Using Technique

[contentblock id=google-adsense-post]

Simply by adding b + c = 100 and a + c = 150, we know that a + b+ 2c = 250. This means that a + b + c has to be less than a + b + 2c (i.e $250). This eliminates all options except ‘1’.

(Ans: 1)

Estimated Time to arrive at the answer = 5 seconds.
[starrater tpl=10]

[contentblock id=smartmath-blockquote]

Leave a Reply

Your email address will not be published. Required fields are marked *