Here’s and example of a SMART MATH problem for RATIO PROPORTION.
Problem
A, B and C are mixed together and their volumes are in the ratio 4 : 5 : 6 respectively. If the weights of equal volumes of A, B and C are in the ratio 2 : 3 : 4, what is the weight of the heaviest substance, if the weight of the mixture is 1123.84 lbs.
- 573.88 lbs
- 673.88 lbs
- 473.88 lbs
- 773.88 lbs
- cannot be determined
The Usual Method
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The ratio of weights of A, B and C in the mixture is = 8 : 15 : 24.
From this it is obvious that C will have the most weight. Hence the quantity of C in the mixture is:
573.88 lbs
(Ans: 1)
Estimated Time to arrive at the answer = 60 seconds.
Using Technique
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First get the ratio of weights of A, B and C in the mixture i.e. 8 : 15 : 24 ( )
From this it is obvious that quantity of C is approximately equal to that of the sum of A and B. In other words, C constitutes almost half of the total mixture. Hence, just divide 1123.84 by 2. This can be done by approximation by dividing 1120 by 2 i.e. 560. Hence the answer should be close to 560. The only option closest to it is 573.88 lbs which is the answer.
(Ans: 1)
Estimated Time to arrive at the answer = 30 seconds.
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