Match List-I with List-II
| List-I (Statements/Expressions etc.) | List-II (Values, etc.) |
|---|---|
| (A) Find the sum of the first 20 odd natural numbers. | (I) 285 |
| (B) How many prime numbers are there between 100 and 200? | (II) 0 |
| (C) Find the sum of the squares of the digits from 1 to 9. | (III) 400 |
| (D) Find the unit's digit in the product 81 X 82 X 83 X ... ... ... 89? | (IV) 21 |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
The sum of the first n odd numbers is n2, so the first twenty add up to 202 = 400 (A - III). There are 21 primes between 100 and 200 (B - IV).
The squares of 1 to 9 add up to 1 + 4 + 9 + 16 + 25 + 36 + 49 + 64 + 81 = 285 (C - I). The product 81 × 82 × … × 89 contains 85 and several even numbers, so it has a factor of 10 and its unit digit is 0 (D - II).