Question

f which is the largest 5digit number which is exactly divide 20,25,35

Answer 1

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• What is the least 5-digit number which is exactly divisible by 20, 25, and 30?
• There are two depending on how you define least. They are 10200, or -99900.

Well first look for the LCM(least common multiple) for 20, 25, and 30.

• 20=2×2×5
• 25=5×5
• 30=2×3×5

All have 5 in common as a common factor, but 25 has two factors of 5 so both must be included. Thirty is the only number that has 3 as a factor, so that must be included. Twenty and 30 both have a common factor of 2, but 20 has two factors of 2 so both must be included. So that gives an LCM of 2×2×3×5×5=300