Home
Class 7
MATHS
What is the least number which when divi...

What is the least number which when divided by 36 , 38 , 57 , 114 and 19 leaves the remainder 26 , 28 , 47 , 104 and 9 respectively ?

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem of finding the least number which, when divided by 36, 38, 57, 114, and 19, leaves the remainders 26, 28, 47, 104, and 9 respectively, we can follow these steps: ### Step 1: Set up the equations We know that for each divisor \( d \) and remainder \( r \), the relationship can be expressed as: \[ X = d \cdot q + r \] where \( q \) is the quotient. We can rearrange this to: \[ X - r = d \cdot q \] This means \( X - r \) must be a multiple of \( d \). ### Step 2: Write down the equations From the information given: 1. \( X - 26 = 36k \) (for some integer \( k \)) 2. \( X - 28 = 38m \) (for some integer \( m \)) 3. \( X - 47 = 57n \) (for some integer \( n \)) 4. \( X - 104 = 114p \) (for some integer \( p \)) 5. \( X - 9 = 19q \) (for some integer \( q \)) ### Step 3: Find the differences From the equations, we can express \( X \) in terms of the remainders: - \( X = 36k + 26 \) - \( X = 38m + 28 \) - \( X = 57n + 47 \) - \( X = 114p + 104 \) - \( X = 19q + 9 \) ### Step 4: Calculate the common differences We can observe that the differences between each divisor and its respective remainder are: - \( 36 - 26 = 10 \) - \( 38 - 28 = 10 \) - \( 57 - 47 = 10 \) - \( 114 - 104 = 10 \) - \( 19 - 9 = 10 \) This indicates that \( X - r \) is consistently 10 less than each divisor. ### Step 5: Find the LCM of the divisors Now, we need to find the least common multiple (LCM) of the divisors: 36, 38, 57, 114, and 19. Using the prime factorization method: - \( 36 = 2^2 \times 3^2 \) - \( 38 = 2 \times 19 \) - \( 57 = 3 \times 19 \) - \( 114 = 2 \times 3 \times 19 \) - \( 19 = 19^1 \) The LCM is found by taking the highest power of each prime: - \( 2^2 \) from 36 - \( 3^2 \) from 36 - \( 19^1 \) from any of the numbers Thus, the LCM is: \[ \text{LCM} = 2^2 \times 3^2 \times 19 = 4 \times 9 \times 19 = 684 \] ### Step 6: Calculate the least number Since we have established that \( X - r \) is equal to the LCM minus the common difference (10), we can calculate: \[ X = \text{LCM} - 10 = 684 - 10 = 674 \] ### Final Answer The least number \( X \) is **674**. ---
Promotional Banner

Topper's Solved these Questions

  • HCF AND LCM

    S CHAND IIT JEE FOUNDATION|Exercise QUESTION BANK |30 Videos
  • HCF AND LCM

    S CHAND IIT JEE FOUNDATION|Exercise Self Assessment Sheet|10 Videos
  • FRACTIONS

    S CHAND IIT JEE FOUNDATION|Exercise SELF ASSESSMENT SHEET-2|10 Videos
  • LINEAR EQUATIONS IN ONE VARIABLE

    S CHAND IIT JEE FOUNDATION|Exercise Unit Test -2|20 Videos

Similar Questions

Explore conceptually related problems

What is the least number which when divided by 7,9, and 12 leaves the same remainder 1 in each case?

What is the least natural number which when divided by 8, 12, 15 or 16 leaves a remainder of 7?

What is the least number which, when divided by 5,6,8 and 10, leaves a remainder of 2 in each case?

What is the least number which when divided by 15, 18 and 21 leaves remainders 2, 5 and 8 respectively?

Find the least number which when divided by 6,7,8,9 and 12 leaves the remainder '1' in each case.

What is the least number which when divided by 42, 72 and 84 leaves the remainders 25, 55 and 67 respectively ?

Find the least number which when divided by 25, 40 and 60 leaves 9 as the remainder ineach case.