Factory X's bulbs work for over 4000 hours in 59% of cases, whereas factory Y's bulbs work for over 4000 hours in 65% of cases. It is known that factory X supplies 60% of the total bulbs available. What is the chance that a purchased bulb will work for longer than 4000 hours?
Choose the correct answer
A) 66.4 %	B) 61.4 %	C) 77.4 %	D) 65 %	E) 53.9 %

Rationale: "for x , 60 % of 59 % will work . for y , 40 % of 65 % will work . * 40 % is the rest of the bulb supply in the market . so , the probability that a purchased bulb will work is : 0.60 ( 0.59 ) = . 354 0.40 ( 0.65 ) = 0.26 the combined probability then is 35.4 + 26.00 = 61.4 % ans b"
Answer: B