Question

Three numbers which are co-prime to each other are such that the product of the first two is 551 and that of the last two is 1073. The sum of the three numbers is:

• A. $85$
• B. $75$
• C. $65$
• D. $55$

Answer 1

Answer: (A)

$85$

All three numbers are co-prime to each other, So the common factor is 1.

Product of the first two numbers$=551$

Product of the last two numbers$=1073$

HCF of $551$ and$1073$ is the middle number.

Middle number,$HCF(551,1073)=29$

First number$=\frac{551}{29}$

$=19$

Last number $=\frac{1073}{29}$

$=37$

Sum of the three numbers $=19+29+37=85$