Mathematics
The difference between digits of a two-digit number is 2 and the product of digits is 24. If tens digit is bigger, the number is :
24
26
46
64
Answer
Let ten's digit be x and one's digit be y.
Given,
Ten's digit is bigger and difference between digits = 2.
∴ x - y = 2
⇒ x = 2 + y …….(1)
Given,
Product of digits = 24
⇒ xy = 24
⇒ y(2 + y) = 24 …….[From Eq. (1)]
⇒ 2y + y2 = 24
⇒ y2 + 2y - 24 = 0
⇒ y2 + 6y - 4y - 24 = 0
⇒ y(y + 6) - 4(y + 6) = 0
⇒ (y - 4)(y + 6) = 0
⇒ y - 4 = 0 or y + 6 = 0
⇒ y = 4 or y = -6.
Since, digit cannot be negative.
∴ y ≠ -6.
x = 2 + y = 2 + 4 = 6.
Number = 10x + y = 10 × 6 + 4 = 60 + 4 = 64.
Hence, Option 4 is the correct option.
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The product of two whole numbers, each greater than 4, is 35; the numbers are :
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Three years hence, the ages of Radha and Meena will be in the ratio 5 : 2. If the sum of their present ages is 62 years, their ages, 2 years ago, were:
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none of these