Question

Read the given instructions to identify the correct number.
(i) The number is greater than 3 Tens.
(ii) It is less than half of 80.
(iii) The difference between the digits in Tens and Ones places of the number is 3.

• A. $25$
• B. $47$
• C. $38$
• D. $36$

Answer 1

The correct option is D $36$

Say:
We have to identify the correct number based on the given instructions.

Steps:
$\bullet$ 3 Tens = 30
$\bullet$ So, as per the first instruction, the number should be greater than 30.
$\bullet$ Half of 80 means a number when subtracted from 80 will give the same number as the difference.
$\bullet$ So, 80 – 40 = 40
$\bullet$ So, as per the second instruction, the number should be less than 40.
$\bullet$ As per the third instruction, the difference between the Tens and Ones place values of the number should be 3.
$\bullet$ Let us consider the options one by one.
$\bullet$ Option A: 47
$\bullet$ 47 is greater than 40, which does not satisfy the second instruction.
$\bullet$ So, it cannot be the correct answer.
$\bullet$ Option B: 25
$\bullet$ 25 is less than 30, which does not satisfy the first instruction.
$\bullet$ So, it also cannot be the correct answer.
$\bullet$ Option C: 38
$\bullet$ 38 is greater than 30 and less than 40, which satisfies the first two instructions.
$\bullet$ Difference between the digits: 8 – 3 = 5.
$\bullet$ It does not satisfy the third instruction.
So, it cannot be the correct answer.
$\bullet$ Option D: 36
$\bullet$ 36 is greater than 30 and less than 40, which satisfies the first two instructions.
$\bullet$ Difference between the digits: 6 – 3 = 3.
$\bullet$ It satisfies the third instruction as well.
$\bullet$ Hence, Option D is correct.

Q: 47 can also be one of the correct options because the difference between the digits in its place values is 3. Is that correct? Why?
A: No, because though the difference between the digits in its place values is 3, based on the second instruction, it is greater than half of 80.