Question

If all 6s get inverted and become 9s, by how much will the sum of all nos. Between 1 and 100 both inclusive change?

Answer 1

Answer:

330

Step-by-step explanation:

When 6's at unit place is changed to 9, value will increase by 3. There are 10 such numbers.

When 6's at 10's place is changed to 9, value will increase by 30. There are 10 such numbers.

For 6's at unit place : 10 * 3 = 30

For 6's at 10s place : 10 * 30 = 300

So the answer is 30 + 300 = 330