Wednesday, April 18, 2007

"ALGEBRA QUESTION OF THE DAY"

A number, when divided by 12, gives a remainder of 7. If the same number is divided by 6, then the
remainder must be
(A) 1 (B) 2 (C) 3 (D) 4 (E) 5

5 comments:

  1. CORRECT ANS IS
    We are told that the remainder is 7 when the number is divided by 12. Hence, we can represent the
    number as 12x + 7. Now, 7 can be written as 6 + 1. Plugging this into the expression yields
    12x + (6 + 1) =
    (12x + 6) + 1 = by regrouping
    6(2x + 1) + 1 by factoring 6 out of the first two terms
    This shows that the remainder is 1 when the expression 12x + 7 is divided by 6. The answer is (A).
    Method II (Substitution):
    Choose the number 19, which gives a remainder of 7 when divided by 12. Now, divide 19 by 6:
    19
    6
    =
    3
    1
    6
    This shows that 6 divides into 19 with a remainder of 1. The answer is (A).

    ReplyDelete