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a, b, c, d are positive integers. When a is divided by b, the remainde
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16 Oct 2017, 02:33
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a, b, c, d are positive integers. When a is divided by b, the remainder is 7. When c is divided by d, the remainder is 5. Which of the following cannot be the value of the product b x d? A. 48 B. 56 C. 63 D. 69 E. 140
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Re: a, b, c, d are positive integers. When a is divided by b, the remainde
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16 Oct 2017, 03:06
nkmungila wrote: a, b, c, d are positive integers. When a is divided by b, the remainder is 7. When c is divided by d, the remainder is 5. Which of the following cannot be the value of the product b x d?
A. 48 B. 56 C. 63 D. 69 E. 140 Hi.... Remainders should tell us that b>7 and d>5... So what can we say about the products.. 1) minimum value 8*6=48 2) atleast two factors above 5, one out of which above 7.. Let's see the choices A) 486*8... Ok B) 56  7*8...ok C) 63  7*9... Ok D) 69  3*23... No other possibilities.. Answer E) 140  7*20... Ok D
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Re: a, b, c, d are positive integers. When a is divided by b, the remainde
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17 Oct 2017, 10:48
nkmungila wrote: a, b, c, d are positive integers. When a is divided by b, the remainder is 7. When c is divided by d, the remainder is 5. Which of the following cannot be the value of the product b x d?
A. 48 B. 56 C. 63 D. 69 E. 140 Recall that the remainder must be less than the divisor; thus, b must be greater than 7 since “when a is divided by b, the remainder is 7.” Similarly, d must be greater than 5 since “when c is divided by d, the remainder is 5.” Since b and d are positive integers, b ≥ 8 and d ≥ 6. Next we can factor each answer choice. If the number can be factored into two numbers such that one of them is at least 8 and the other is at least 6, then it can be a value of b x d. However, if the number can’t be factored in the way described above, then it CANNOT be a value of b x d and that is the number we are looking for. A. 48 = 8 x 6 (Yes) B. 56 = 8 x 7 (Yes) C. 63 = 9 x 7 (Yes) D. 69 = 1 x 69 = 3 x 23 (No) E. 140 = 20 x 7 (Yes) Since 69 can only be factored as 1 x 69 or 2 x 23, we don’t have one factor ≥ 8 and the other ≥ 6, so 69 can’t be a value of b x d. Answer: D
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Re: a, b, c, d are positive integers. When a is divided by b, the remainde
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12 Nov 2017, 16:30
pushpitkc wrote: a,b,c,d are positive integers. When a is divided by b, the remainder is 7. When c is divded by d, the remainder is 5. Which of the following cannot be the value of the product b * d? A. 48 B. 56 C. 63 D. 69 E. 140 Source: Experts GlobalHi.. The Q is to do more with factors than anything else.. What message can you take from remainders b>7 and d>5 Let's see if the choices can be converted to factors that fit in 48=8*6...yes 56=8*7...yes 63=9*7...yes 69=23*3 or 1*69....NO 140=14*10...yes Ans D..69
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1) Absolute modulus : http://gmatclub.com/forum/absolutemodulusabetterunderstanding210849.html#p1622372 2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html 3) effects of arithmetic operations : https://gmatclub.com/forum/effectsofarithmeticoperationsonfractions269413.html
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Re: a, b, c, d are positive integers. When a is divided by b, the remainde
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29 Oct 2018, 23:24
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