The average of 8 readings is 24.3, out of which the average of first two is 18.5 and that of next three is 21.2. If the sixth reading is 3 less than seventh and 8 less than eight, what is the sixth reading? 

A motorboat, whose speed is 45 km./hr. in still water goes 180 km. downstream and comes back in a total of 9 hours. The speed of the stream (in km/hr.) is-

An article is sold at a loss of 20 %. It yields Rs. 60 more when it is sold at a gain of 20 %. The cost price of the article is 

A party for 50 people was organized at their own expense. 48 of them paid Rs 950 each, while the other two paid Rs 1200 more than the group's average expenditure. The total expenditure incurred was.

In a group of students, 70 % can speak English and 65 % can speak Hindi. If 27 % of the students can speak none of the two languages, then what percent of the group can speak both the languages? 

If the income of A is 10% more than that of B and the income of B is 20% less than that of C, then the incomes of A, B and C respectively are in the ratio

What will come in place of the question mark (?) in each of the following series?

15     18    16   19     17    20    ?

Directions : What should come in place of the question mark (?) in the following number series? 

55 109 ? 433 865 1729