Missing factors to find the given estimated product of 6,397×349

Afactory buys 10% of its components from suppliers b and the rest from supplier c. it is known that 6% of the components it buys are faulty. of the components brought from suppliers a,9% are faulty and of the components bought from suppliers b, 3% are faulty. find the percentage of components bought from supplier c that are faulty.

Me on this i beg you on this to answer!

What is the least common multiple of 8, 12, 7