The sum of two numbers is 36. Their H.C.F. and L.C.M. are 3 and 105…
2016
The sum of two numbers is 36. Their H.C.F. and L.C.M. are 3 and 105 respectively. The sum of reciprocals of those two numbers will be
- A.
1/3
- B.
7/35
- C.
4/35
- D.
9/11
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Correct answer: C
Let the two numbers be 3a and 3b, where a and b are co-prime (since H.C.F. is 3).
Given that their sum is 36:
3a + 3b = 36
Divide both sides by 3:
a + b = 12
Also, L.C.M. of the two numbers is 3ab = 105.
So, 3ab = 105 → ab = 35.
Now, we need to find the sum of reciprocals:
1/(3a) + 1/(3b) = (b + a)/(3ab)
Substitute a + b = 12 and ab = 35:
(12)/(3 × 35) = 12/105 = 4/35.
Therefore, the sum of reciprocals is 4/35.
हिन्दी उत्तर:
मान लीजिए दो संख्याएँ 3a और 3b हैं, जहाँ a और b सह-अभाज्य हैं (क्योंकि म.स. 3 है)।
दिया गया है कि उनका योग 36 है:
3a + 3b = 36
दोनों तरफ 3 से भाग देने पर:
a + b = 12
इसके अलावा, दोनों संख्याओं का ल.स. 3ab = 105 है।
तो, 3ab = 105 → ab = 35।
अब, हमें व्युत्क्रमों का योग ज्ञात करना है:
1/(3a) + 1/(3b) = (b + a)/(3ab)
a + b = 12 और ab = 35 का प्रतिस्थापन करने पर:
(12)/(3 × 35) = 12/105 = 4/35।
इसलिए, व्युत्क्रमों का योग 4/35 है।
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