Question

A boy has drawn a number card from a bag containing numbers from 1 to 100. He takes out a number from the bag which is 20 more than the smallest two-digit number. What is his number?

Answer 1

Hint: Let the number drawn by the boy to be a variable x. Also, use the fact that the smallest two-digit natural number is 10.

Complete step-by-step answer:
See, in such questions, the general meaning of the term number is actually natural numbers. So, we can say that the bag contains cards with natural numbers 1 – 100 written on them. Now a boy picks a card from these numbers. Let the number on the drawn card be x.
It is also given in the question that the number drawn is 20 more than the smallest two-digit natural number.
Now, if we think a bit, we will reach a result that the smallest two-digit natural number is 10. So, using this fact, we can form a mathematical equation in terms of x, which comes to be:
$\text{drawn number=smallest two digit number+20}$
$\Rightarrow \text{x=10+20}$
$\Rightarrow x=30$
Therefore, we can say that the card drawn by the boy from the bag of cards with numbers 1-100 printed on them contains the number 30 printed on it.

Note: Always think about the facts carefully as a general mistake a student does in such problems is they take 11 to be the smallest two-digit number missing that 10 is the smallest two-digit number resulting in an incorrect answer.