Q. A manufacturer builds a machine which will address 500 envelopes in 8 minutes. He wishes to build another machine so that when both are operating together they will address 500 envelopes in 2 minutes. The equation used to find how many minutes x it would require the second machine to address 500 envelopes alone, is = ?

• (A) 8−x=2
• (B) 1/8 + 1/x = 1/2
• (C) 500/8 + 500/x = 500
• (D) x/2 + x/8 =1