.The ten digits is 5 more than the units digit.The sum of the digit of a two-digit number is 3 less than one-fifth the number.
Answers
The correct answer is -60.
Given:
A number such that the ten's digit is 5 more than the unit's digit.
The sum of the digits of the two-digit number is 3 less than one-fifth of the number.
To Find:
The required number.
Solution:
We have to find a two-digit number such that the ten's digit is 5 more than the unit's digit and the sum of its digits is 3 less than one-fifth the number.
Let us assume that the one place of the two-digit number is 'u' and the tens place is ''.
⇒ The required number = 10t+u
We are given that the ten's digit is 5 more than the unit's digit of this number. The above statement in equation form is:
t = u+5
⇒ t-u = 5 .......................(I)
Also, the sum of its digits is 3 less than one-fifth of the number. The above statement in equation form is:
t+u = (10t+u)/5 - 3
⇒ 5(t+u) = 10t+u - 15
⇒ 10t+u - 5(t+u) = 15
⇒ 5t -4u = 15 ........................(II)
Multiplying equation (I) by -5, we get
-5t + 5u = -25 ........................(III)
Adding equations (II) and (III), we get:
( 5t -4u) + (-5t + 5u) = 15-25
u = -10
Substituting the above value in equation (I), we have
t-u = 5
⇒ t -(-10) = 5
⇒ t = -5
Hence the required number = 10t+u = 10(-5)+(-10) = -60.
∴ The correct answer is -60.
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Answer:
The required to digit number is -60.
Step-by-step explanation:
Given :
Ten digit is 5 more than the units digit.
Also , the sum of the digit of a two-digit number is 3 less than one-fifth the number.
To find :
The unknown two digit number.
Solution :
Let the units digit be x and tens digit be y
Then as given, ten digits is 5 more than the units digit, so y = x+5 ----eq.(1)
the required number is 10y + x .
Also , the sum of the digit of a two-digit number is 3 less than one-fifth the number.
⇒ y + x =1/5 × (10y + x) -3
⇒5( y + x )= 10 y + x -(3×5)
⇒5y + 5x = 10y + x -15
⇒5x - x = 10y -5y -15
⇒4x =5y - 15 ---------eq.(2)
putting y = x +5 in eq. (2) we get ,
4x = 5(x + 5) - 15
4x = 5x +25 -15
5x - 4x = -25 + 15
x= -10
substituting x= -10 in eq. (1)
Therefore y = x+5 = -10 +5
y = -5
∴The required two digit number is
10y + x = 10×(-5) + (-10) = -50 - 10 = -60.
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