Find the fourth consecutive even number:
(I) The sum of the last two numbers is 30
(II) The sum of the first two numbers is 22
number
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- Vemuri
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IMO D
Let the 4 consecutive numbers be a, a+2, a+4, a+6
Stmt1: Sum of last 2 numbers, i.e. (a+4) + (a+6) = 30 ==> 2a+10 = 30 ==> a = 10. So, the fourth even number is a+6 ==> 16. Sufficient.
Stmt2: Sum of first 2 numbers, i.e. a + (a+2) = 22 ==> 2a+2 = 22 ==> a = 10. So, the fourth even number is a+6 ==> 16. Sufficient.
Let the 4 consecutive numbers be a, a+2, a+4, a+6
Stmt1: Sum of last 2 numbers, i.e. (a+4) + (a+6) = 30 ==> 2a+10 = 30 ==> a = 10. So, the fourth even number is a+6 ==> 16. Sufficient.
Stmt2: Sum of first 2 numbers, i.e. a + (a+2) = 22 ==> 2a+2 = 22 ==> a = 10. So, the fourth even number is a+6 ==> 16. Sufficient.
please explain, how do we know the no. of numbers are there in the sequence.Vemuri wrote:IMO D
Let the 4 consecutive numbers be a, a+2, a+4, a+6
Stmt1: Sum of last 2 numbers, i.e. (a+4) + (a+6) = 30 ==> 2a+10 = 30 ==> a = 10. So, the fourth even number is a+6 ==> 16. Sufficient.
Stmt2: Sum of first 2 numbers, i.e. a + (a+2) = 22 ==> 2a+2 = 22 ==> a = 10. So, the fourth even number is a+6 ==> 16. Sufficient.
- Vemuri
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I am making a lot of silly mistakes today. My bad. I agree with kic883's explanation. The answer should be B.ketkoag wrote: please explain, how do we know the no. of numbers are there in the sequence.