Problems on Numbers
Q1. The sum of three consecutive numbers is 93. The greatest among these three numbers is
(a) 27
(b) 28
(c) 30
(d) 32
Answer: (d) 32
Let the three numbers are x, x+1 and x+2
Then x+(x+1)+(x+2)=93
3x=90
x=30
Greater Number=(x+2)=32
Q2. The sum of four consecutive even integers is 1092. The greatest of them is
(a) 270
(b) 300
(c) 276
(d) 302
Answer: (c) 276
Let the four integers be x, x+2, x+4 and x+6
Then x+(x+2)+(x+4)+(x+6)=1092
4x=1080
x=270
Greater Number=(x+6)=276
Q3. The sum of three consecutive odd numbers is 10 more then the first of these numbers. What is the greatest number
(a) 6
(b) 8
(c) 9
(d) 12
Answer: (a) 6
Let the four integers be x, x+2 and x+4
Then x+(x+2)+(x+4)=x+10
2x=4
x=2
So the Greatest Number is=(2+4)=6
Q4. The difference of the squares of two consecutive odd numbers is 84. What is the sum of the two numbers
(a) 40
(b) 42
(c) 45
(d) 48
Answer: (b) 42
Let the two numbers is x and x+2
Then (x+2)2 - x2=84
4x+4=84
x=20
Required Sum is=x+(x+2)=42
Q5. The difference between two numbers is 5 and their sum is 65. What will be their product
(a) 325
(b) 650
(c) 755
(d) 1050
Answer: (d) 1050
Let the two numbers is X and Y
X-Y=5
X+Y=65
2X=70
X=35, so Y is 30
So X*Y = 1050
Q6. 759 X 568 + 759 X 432 = ?
(a) 756800
(b) 759000
(c) 568000
(d) 432000
Answer: (b) 759000
=759 X 568 + 759 X 432
=759 (568 + 432)
=759 X 1000
=759000
Q7. 832 X 455 - 832 X 355 = ?
(a) 83200
(b) 82300
(c) 8320
(d) 832000
Answer: (a) 83200
=832 X 455 - 832 X 355
=832 (455 - 355)
=832 X 100
=83200
Q8. 105 X 105
(a) 10500
(b) 11250
(c) 11520
(d) 11025
Answer: (d) 11025
=105 X 105
=(105)2
=(100 + 5)2
=1002 + (2 X 100 X 5) + 52 Formula [(a+b)2=a2+2ab+b2]
=10000 + 1000 + 25
=11025
Q9. 96 X 96
(a) 9216
(b) 9261
(c) 9006
(d) 9466
Answer: (a) 9216
=96 X 96
=(96)2
=(100 - 4)2
=1002 - (2 X 100 X 4) + 42 Formula [(a-b)2=a2-2ab+b2]
=10000 - 800 + 16
=9200 + 16
=9216
Q10. 456 X 456 - 302 X 302
(a) 128734
(b) 118564
(c) 116732
(d) 127856
Answer: (c) 116732
=456 X 456 - 302 X 302
=(456)2 - (302)2
=(456+302) - (456-302) Formula [a2 - b2=(a+b)(a-b)]
=758 X 154
=116732
Practice Test Exam