In an examination of Hindi, English and Mathematics subjects, the maximum marks are 120, 140 and 100 respectively. A student obtains 40%, 55% and 45% marks respectively in these subjects. How many marks should he obtain in the science subject, whose total marks are 180, so that the combined percentage of marks obtained in all the four subjects becomes 60%?

Explanation

Maximum marks for Hindi, English, Math and Science $= 120 + 140 + 100 + 180 = 540$ Total marks obtained in all three subjects $$= 120 \times \frac{40}{100} + 140 \times \frac{55}{100} + 100 \times \frac{45}{100}$$ $$= 48 + 77 + 45 = 170$$ $60\%$ of the total marks' $= 540 \times \frac{60}{100} = 324$ $\therefore$ Required marks in science $= 324 - 170 = 154$ Therefore, option (c) is the correct answer.