If the cost of a long distance phone call is C taka for the first minute and (2/3) C taka for each additional minute, what is the cost, in taka, of a 10 minute call of this type?
সমাধান
সঠিক উত্তর: Option D
first minute cost =c then, remaining 9 minute cost = 9 X 2/3 c=18/3 c total cost = (c+18/3 c)= 21/3 c =7 c
