Question

Find the largest five digit number that is divisible by 7, 10, 15, 21 and 28.

• A. 75758
• B. -75758
• C. 99960
• D. -99960

Answer 1

The correct option is C 99960

$LCM$ of $7,10,15,21,28$ is $7\times 2\times 5\times 3\times 2=420$

the five digits number must be multiple of $420$

the largest number must be multiple of $LCM$

$\therefore$ the largest four digits number is $420\times 238=99960$