Page 92 - Ganit Kaushal

Ex 10. The number of whole numbers between 38 and 68 is (NCERT Exemplar)

(a) 31 (b) 30 (c) 29 (d) 28
Sol. (c) The number of whole numbers between 38 and 68 is 39, 40, 41, …, 67.
Thus, there are 29 whole numbers between 38 and 68.
Ex 11. A whole number is added to 25, and the same number is subtracted from 25. The sum of the resulting
numbers is (NCERT Exemplar)
(a) 0 (b) 25 (c) 50 (d) 70

Sol. (c) Let the whole number be 15. Adding 15 to 25 gives 25 + 15 and subtracting 15 from 25 gives
25 – 15.

\ Sum of results = (25 + 15) + (25 – 15) = 40 + 10 = 50
Ex 12. Fill in the blanks.
(a) 1 lakh = _______ ten thousand (b) 1 million = _______ hundred thousand
(c) 1 crore = _______ ten lakh (d) 1 crore = _______ million
(e) If the Kaprekar procedure is repeatedly applied to a few three-digit numbers, the number that starts
repeating is _______ .

(f) By adding 1 to the greatest _______ digit number we get ten lakh. (NCERT Exemplar)
(g) Writing numbers from the greatest to the smallest is called an arrangement in _______ order.
(NCERT Exemplar)
(h) Division of a whole number by _______ is not defined. (NCERT Exemplar)
(i) The number 641146 is a _______ .
Sol. (a) 1 lakh = 10 ten thousand [ 1 lakh = 1,00,000 and ten thousand = 10,000]

(b) 1 million = 10 hundred thousand [ 1 million = 1,000,000 and 1 hundred thousand = 1,00,000]
(c) 1 crore = 10 ten lakhs [ 1 crore = 1,00,00,000 and ten lakhs = 10,00,000]
(d) 1 crore = 10 million [ 1 crore = 1,00,00,000 and 1 million = 1,000,000]
(e) 495 (f) 6 (g) descending (h) 0
(i) palindrome

Ex 13. State whether the given statements are True (T) or False (F).
(a) Zero is the smallest natural number. (b) The number 6410646 is a palindrome.
(c) All natural numbers are whole numbers. (d) All whole numbers are natural numbers.
(e) 1 is the smallest whole number. (f) The whole number 13 lies between 11 and 12.

(g) 6147 is the Kaprekar number.
(h) Palindromic numbers are those which read the same from both sides.
(i) Writing of numbers from the smallest to the greatest is called an arrangement in increasing
order.
(j) 10, 5, 18, 8, 4, 2, 1 is a Collatz sequence.
(k) Using the division algorithm, we can write 37 = 7 × 4 + 9, where 4 is the quotient and 9 is the remainder.
Sol. (a) False, since 0 is a whole number, not a natural number.

(b) False, since it is not the same from the left and right.
(c) True

90 Mathematics-6