A mobile battery in 1 hour charges to 20 percent.How much time (in minute) will it require more to charge to 50 percent. Answers:  A) 145  B) 150  C) 175  D) 160  E) 130

Rationale: 1 hr = 20 percent . thus 15 min = 5 percent . now to charge 50 percent 150 min . answer : b
Answer: B