TheCATExam
Sign in

CAT 1999 — QA Question 2

Unit's DigitEasy

Let a, b, c be distinct digits. Consider a two-digit number ‘ab’ and a three-digit number ‘ccb’, both defined under the usual decimal number system, if (ab)2 = ccb > 300, then the value of b is

Answer & solution

  • 1

  • B

    0

  • C

    5

  • D

    6

Solution

(ab)2 = ccb, the greatest possible value of ‘ab’ to be 31.

Since 312 = 961 and since ccb > 300, 300 < ccb < 961, so 18 < ab < 31.

So the possible value of ab which satisfies (ab)2 = ccb is 21.

So 212 = 441,

∴ a = 2, b = 1, c = 4.

Hence, option (a).

CAT 1999 QA Q2: Let a, b, c be distinct digits. Consider a two-digit number &lsquo;ab&rsquo; and a three-digit number &lsquo;c — Solution | TheCATExam