A person X wants to distribute some pens among six children A, B, C, D, E and F. Suppose A gets twice the number of pens received by B, three times that of C, four times that of D, five times that of E and six times that of F. What is the minimum number of pens X should buy so that the number of pens each one gets is an even number?
Correct Answer :
294
Solution :
The correct option is 294.
Let the number of pens received by children A, B, C, D, E, and F be denoted by , , , , , and respectively.
According to the given condition, A gets:
- twice the number of B: ⇒
- three times that of C: ⇒
- four times that of D: ⇒
- five times that of E: ⇒
- six times that of F: ⇒
The total number of pens distributed, let's call it T, is:
Substituting the relations in terms of :
To simplify this expression, we find the Least Common Multiple (LCM) of the denominators 2, 3, 4, 5, and 6, which is 60. Taking the common denominator:
Since the number of pens each person gets must be an integer, must be a multiple of 60 to cancel out the denominator. Let , where is a positive integer.
If we substitute , the shares of each child become:
-
-
-
-
-
-
We are given the condition that the number of pens each one gets must be an even number. Let us check the shares for different values of :
If , then , which is an odd number. Therefore, must be an even integer to ensure that is even (since 60, 30, 20, 12, and 10 are already even coefficients, their products with any integer are even, but 15 requires an even multiplier).
The smallest positive even integer for is:
Substituting back into the total pen count equation:
Thus, the minimum number of pens X should buy is 294.
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