Chapter 1: Number System

Solution:-

(C) 400000

The product of the place values of two 2’s in 428721 is

There are two 2’s in the given number.

So, the first 2 are in the tenth place,

Then, the product is = 2 × 10

= 20

The other 2 is in place value of ten thousand.

Then, = 2 × 10000

= 20000

Therefore, the product of place values = 20 × 20000

= 400000

Solution:-

(C) 37904

3 × 10000 = 30000

The place value is 30000

7 × 1000 = 7000

The place value is 7000

9 × 100 = 900

The place value is 900

0 × 10 = 0

4 = 4

Therefore, the sum of all place value is = 30000 + 7000 + 900 + 0 + 4

= 37904

Solution: –

(D) 1 crore

We know that, the greatest number is 99,99,999

Then, 1 is added to 99,99,999 = 99,99,999 + 1

= 1,00,00,000

= 1 crore

Solution:-

(B) 9 × 1000 + 5 × 100 + 7 × 10 + 8 × 1

Consider the given number 9578,

The place value of 8 is ones = 8 × 1

The place value of 7 is tens = 7 × 10

The place value of 5 is thousand = 5 × 100

The place value of 9 is ten thousand = 9 × 1000

Solution:-

(D) 86000

When rounded off to nearest thousands, the number 85642 is = 86000

Solution:-

(D) 9965

Using 9 as twice from 5, 9, 2 and 6, then the number is 9965.

Solution:-

(C) 5,86,95,376

In Indian System of Numeration, the number 58695376 is written as 5 crore, eighty six lakh, ninety five thousand, three hundred and seventy six = 5,86,95,376

Solution:-

(B) 10 Lakh

One million is equal to ten lakhs.

1,000,000 = 10,00,000

Solution:-

(D) 5499

The greatest number which on rounding off to nearest thousands gives 5000, is 5499.

Solution:-

(C) 6034579

Keeping the place of 6 in the number 6350947 same, the smallest number obtained by rearranging other digits is 6034579.