LCM and HCF
- 21 mangoes trees, 42 apples trees and 56 oranges trees have to be planted in rows such that each row contains the same number of trees one variety only. Minimum number of rows in which the above trees may be planted is ?
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H.C.F. of 21, 42, 56 = 7
Number of rows of mango trees, apple trees and oranges trees are 21/7 = 3, 42/7 = 6 and 56/7 = 8
∴ Required number of rows = (3 + 6 + 8 ) = 17Correct Option: B
H.C.F. of 21, 42, 56 = 7
Number of rows of mango trees, apple trees and oranges trees are 21/7 = 3, 42/7 = 6 and 56/7 = 8
∴ Required number of rows = (3 + 6 + 8 ) = 17
- Five bells begin to toll together and toll respectively at intervals of 6, 7, 8, 9 and 12 seconds. How many times they will toll together in one hour , excluding the one at the start ?
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L.C.M of 6, 7, 8, 9, 12 is 504
So, the bells will toll together after 504 sec.
In hour, they will toll together
= (60 x 60) / 504 times
= 7 timesCorrect Option: C
L.C.M of 6, 7, 8, 9, 12 is 504
So, the bells will toll together after 504 sec.
In hour, they will toll together
= (60 x 60) / 504 times
= 7 times
- Three different containers contain different qualities of mixtures of milk and water, whose measurement are 403 kg, 434 kg and 465 kg. What biggest measure must be there to measure all the different qualities exactly ?
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Biggest measure = H.C.F. of 403, 434 and 465
Correct Option: A
Biggest measure = H.C.F. of 403, 434 and 465
= 31 kg
- Three pieces of timber 42 m, 49 m and 63 m long have to be divided into planks of the same length, What is the greatest possible length of each plank ?
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Greatest possible length of each plank = H.C.F of 42, 49, 63
Correct Option: A
Greatest possible length of each plank = H.C.F of 42, 49, 63 = 7 m
- Six bells commence tolling together and toll intervals of 2, 4, 6, 8, 10 and 12 seconds respectively. In 30 minutes, how many times do they toll together ?
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L . C . M of 2, 4, 6, 8, 10 and 12 is 120
So the bells will toll together after 120 second i,e 2 minutes. In 30 min. they will together in (30/2) + 1 times, i.e 16 times.Correct Option: D
L . C . M of 2, 4, 6, 8, 10 and 12 is 120
So the bells will toll together after 120 second i,e 2 minutes. In 30 min. they will together in (30/2) + 1 times, i.e 16 times.
