Question

Find the smallest number which when (a) decreased by 1 (b) increased by 3. Is exactly

divisible by the number 21, 45, 63, 81 and 210​

Answer 1

Answer:

4 is the number which when decreased by 1 exactly divisible by 21, 45, 63, 81 and 210​.

Answer 2

Step-by-step explanation:

first we find the HCM of 21 , 45 63 , 81 and 210

3 |. 21 , 45 , 63 , 81 , 210

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3 | 7 , 15 , 21 , 27 , 70

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5 | 7 , 5 , 7 , 9 , 70

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7 | 7 , 1 , 7 ,. 9 ,. 14

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1, 1 ,. 1 , 9 ,. 2