LCM of two numbers is 138. But their (Greatest common divisor) GCD is 23. The numbers are in a ratio 1:6. Which is the largest number amongst the two?
Correct answer: B. 138
- A. 46
- B. 138
- C. 69
- D. 23
Explanation
Let the numbers be x and 6x because their ratio is 1:6. Their GCD is x and their LCM is 6x, so 6x = 138, giving x = 23 and the larger number 6 x 23 = 138. The likely mistake is choosing 23, which is the GCD and smaller number, not the larger number.
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Ratios compare quantities in the same units, while proportions state that two ratios are equal. Problems cover simplification, division in a given ratio, direct and inverse variation, scale, and missing terms, with attention to the difference between a ratio and a fraction representing part of a whole.
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