Problems on Numbers Questions Answers
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8. The product of two numbers is 120 and the sum of their squares is 289. The sum of the number is
- 20
- 23
- 27
- 150
Answer And Explanation
Answer: Option B
Explanation:
We know
(x+y)2=x2+y2+2xy
=>(x+y)2=289+2(120)
=>(x+y)=√529=23 -
9. Three times the first of three consecutive odd integers is 3 more than twice the third. The third integer is
- 12
- 13
- 15
- 17
Answer And Explanation
Answer: Option C
Explanation:
Let the three integers be x, x+2 and x+4.
Then, 3x = 2(x+4)+3,
x= 11
Therefore, third integer x+4 = 15 -
10. Find the number which when multiplied by 15 is increased by 196
- 10
- 12
- 14
- 16
Answer And Explanation
Answer: Option C
Explanation:
Let the number be x.
Then, 15x = x + 196
=› 14 x= 196
=› x = 14. -
11. if the sum of 12
and 15of a number exceeds 13of the number by 713, then number is- 15
- 20
- 25
- 30
Answer And Explanation
Answer: Option B
Explanation:
Seems a bit complicated, isnt'it, but trust me if we think on this question with a cool mind then it is quite simple...
Let the number is x,
then, (12x+15x)−13x=223
=>11x30=223
=>x=20 -
12. find the number, If 50 is subtracted from two-third of number, the result is equal to sum of 40 and one-fourth of that number.
- 214
- 216
- 114
- 116
Answer And Explanation
Answer: Option B
Explanation:
Let the number is x,
=>23x−50=14x+40
<=>23x−14x=90
<=>5x12=90
<=>x=216 -
13. Product of two natural numbers is 17. Then, the sum of reciprocals of their squares is
- 290289
- 1289
- 29090
- 29019
Answer And Explanation
Answer: Option A
Explanation:
If the numbers are a, b, then ab = 17,
as 17 is a prime number, so a = 1, b = 17.
1a2+1b2=112+1172
=290289 - 290289
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14. Sum of three numbers 264, If the first number be twice then second and third number be one third of the first, then the second number is
- 70
- 71
- 72
- 73
Answer And Explanation
Answer: Option C
Explanation:
Let the second number is x, then first is 2x, and third is 1/3(2x)
=>2x+x+2x3=264<=>11x3=264
=>x=72