Arithmatical - HCF and LCM of Numbers
DIRECTIONS : Problems based on HCF and LCM.
11. |
The maximum numbers of students among them 1001 pens and 910 pencils can be distributed in such a way that each student gets the same number of pens and same number of pencils is |
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A. 91 |
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B. 910 |
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C. 1001 |
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D. 1911 |
Solution |
Required number of students. |
= H.C.F of 1001 and 910. |
‹=› 91. |
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Solution |
Clearly, 252 =2 x 2 x 3 x 3 x 7 |
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13. |
Three different containers contain 496 litres, 403 litres and 713 litres of mixtures of milk and water respectively. What biggest measure can measure all the different quantities exactly? |
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A. 1 litre |
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B. 7 litre |
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C. 31 litre |
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D. 41 litre |
Solution |
Required measurement | = H.C.F of (496, 403, 713) litres |
‹=›31 litres. |
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14. |
The H.C.F of two numbers is 8. Which one of the following can never be their L.C.M? |
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A. 8 |
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B. 12 |
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C. 60 |
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D. 72 |
Solution |
H.C.F of two numbers divides their L.C.M exactly. Clearly, 8 is not a factor of 60. |
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15. |
The L.C.M of two numbers is 495 and their H.C.F is 5. If the sum of the numbers is 10, then their difference is |
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A. 10 |
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B. 46 |
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C. 70 |
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D. 90 |
Solution |
Let the numbers be x and (100 - x) . |
Then, x (100 - x) = 5 ×495 |
‹=›x2 - 100x + 2475 = 0. |
‹=› (x -55) (x - 45) = 0. |
x = 55 or x = 45. |
Therefore, the numbers are 45 and 55. |
Required difference = (55 - 45) = 10. |
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