**In a seminar the number of participants in Technology, Economics and Science are 150, 90 and 180 respectively. Find the minimum number of rooms required, where in each room the same number of participants are to be seated and all of them being in the same subject.**

A)27

B)35

C)30

D)25

Answer

Option (c) is correct

**Explanation –**

HCF of 150, 90 and 180 = 30

No of participants can be seated in each room = 30

**Naren, Suraj and Praveen start running around a circular stadium and complete one round in 12s, 9s and 15s respectively. In how much time will they meet again at the starting point ?**

A)2m

B)2.30m

C)3m

D)3.30m

Answer

Option (c) is correct

**Explanation –**

LCM of 12, 9, 15 =180s = 3m

**Three boxes of lengths 60m,30m and 45m are to be cut into pieces of equal length. What is the greatest possible length of each pieces ?**

A)15m

B)18m

C)5m

D)3m

Answer

Option (a) is correct

**Explanation –**

HCF of 60, 30 and 45m = 15m

**In a college, all the students can stand in a row, so that each row has 9, 7 and 12 students. Find the least no of students in the school ?**

A)145

B)265

C)186

D)252

Answer

Option (d) is correct

**Explanation –**

LCM of 9, 7 and 12 = 252

**The HCF of 3 different no is 17, Which of the following cannot be their LCM ?**

A)540

B)289

C)340

D)425

Answer

Option (a) is correct

**Explanation –**

540 cannot be divisible by 17

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