What is the least number to be added to 4400 to make it a perfect square? (a) 87 (b) 91 (c) 93 (d) 89 (e) None of these

Let one of the number be x second number be 5x 2(x+21)=(5x+21) => 2x+42=5x+21 => 2x−5x=21−42 => −3x=−21 x=7 One of the number 7 Second number 7×5=35 Answer : 7,35

(b) 382 = 1444  392 = 1521  Required number = 1521 – 1500 = 21

(a) 392 = 1521 ; 382 = 1444 382 < 1500 < 392 To make1500 a perfect square, 21 should be added to it.

(a) Let the the number be = x According o the question, x2 – 262 = 549 or, x2 – 676 = 549 or, x2 = 549 + 676 = 1225 or, x = √1225...

(b) Let the number be x. x2 + 612 = 5242 x2 = 5242 – 3721 = 1521 x = 39

d) 69 × 69 = 4761 68 × 68 = 4624 Clearly, 4624 < 4700 < 4761 Hence, 61 should be added to 4700 to make it a perfect square.

(c) √3986 = 63.13 The next higher square is (64)2 = 4096 number to be added = 4096 – 3986 =110

(b) 722 Let number be x 56% of a number = 1064 \(\frac{56}{100} \times x = 1064\) \(x = 1064 \times \frac{100}{56}\) x = 1900 ∴ number = 1900 38% of a number = 38% of 1900  = \(1900...

(a) Let the number be = x x = (153x4x100x100)/(3x15x40)= 3400

(a) Let the number be = x According to the question, x/8 = 17.25 or x = 17.25 x 8 = 138 73% of 138 = 138 x 73/100= 100.74