Number System
- How many integers from 1 to 100 exist such that each is divisible by 5 and also has 5 as a digit ?
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5,15,25,35,40,50,55,65,75,85,95
Correct Option: B
5,15,25,35,40,50,55,65,75,85,95
So there are total 11 such type of numbers.
- The sum of the digits of two-digit number is 14 and the difference between the two digits number is 2. What is the product of the two digits of the two-digit number ?
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Let be the ten's digit be x and unit's digit be y.
So the two digit number = 10x + y ( where x > y )
According to question
x + y = 14 ....(i)
x - y = 2 ....(ii)Correct Option: B
Let be the ten's digit be x and unit's digit be y.
So the two digit number = 10x + y ( where x > y )
According to question
x + y = 14 ....(i)
x - y = 2 ....(ii)
Solving Eqs. (i) and (ii), we get
x = 8 and y = 6
∴ Required product = 8 x 6 = 48
- What number should be added to 231228 to make it exactly divisible by 33 ?
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Divide 231228 by 33
Correct Option: C
Given,
33) 231228 ( 7006
231
-----------
228
198
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30
Now, 33 - 30 = 3
∴ On adding 3 to 231228, it is completely divisible by 33.
- How many rational numbers are there between 1 and 1000 ?
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There can be infinite number of rational numbers between 1 and 1000.
Correct Option: D
There can be infinite number of rational numbers between 1 and 1000.
- The sum of 5 consecutive even numbers A, B, C, D and E is 130. What is the product of A and E ?
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Let 5 consecutive even number be A = x, B = x+2, C = x+4, D = x + 6 and E = x + 8.
According to question
x + x +2 + x + 4 + x + 6 + x + 8 = 130Correct Option: C
Let 5 consecutive even number be A = x, B = x+2, C = x+4, D = x + 6 and E = x + 8.
According to question
x + x +2 + x + 4 + x + 6 + x + 8 = 130
⇒ 5x + 20 = 130
⇒ x = 22
∴ A = 22, E = 22 + 8 = 30.
∴ Multiplication of A and E = 22 x 30
= 660
