Find the greatest number by which when the numbers 176 and 273 are divided, it leaves remainders 5 and 3, respectively.
- AOption (a)
10
- BOption (b)
9
- COption (c)
12
- DOption (d)
14
View answer & explanationHide answer & explanation
Correct answer
9
Why this answer is correct
Shortcut Trick
Subtract the remainders from the respective numbers.
176 − 5 = 171
273 − 3 = 270
Find the HCF of 171 and 270.
171 = 9 × 19 and 270 = 9 × 30.
∴ The correct answer is 9.
Alternate Method
Given:
Numbers: 176 and 273
Remainders: 5 and 3
Formula Used:
Required number = HCF of (Number1 − Remainder1) and (Number2 − Remainder2)
Calculations:
⇒ First number = 176 − 5 = 171
⇒ Second number = 273 − 3 = 270
⇒ Prime factorization of 171 = 3 × 3 × 19 = 32 × 19
⇒ Prime factorization of 270 = 2 × 3 × 3 × 3 × 5 = 2 × 33 × 5
⇒ HCF (171, 270) = 32 = 9
∴ The correct answer is 9.
Additional Information
Highest Common Factor (HCF)
HCF is the greatest divisor that divides two or more numbers without leaving a remainder.
HCF with same remainder
To find the greatest number that leaves the same remainder 'r' in each case, calculate HCF(x − r, y − r, z − r).
HCF with unknown same remainder
If the remainder is not given but is same, find the HCF of the differences between the numbers: HCF(|x−y|, |y−z|, |z−x|).