236: Out of the three annual examinations, each with a total of 500 marks, a student secured average marks of 45% and 55% in the first and second annual examinations. To have an overall average of 60%, how many marks does the student need to secure in the third annual examination ?
(a) 450
(b) 400
(c) 350
(d) 300
237: A father is now three times as old as his son. Five years back, he was four times as old as his son. The age of the son is
(a) 12 years
(b) 15 years
(c) 18 years
(d) 20 years
238: Consider the following statements with reference to the Periodic Table of chemical elements :
I. lonisation potential gradually decreases along a period.
II. In a group of elements, electron affinity decreases as the atomic weight increases.
III. In a given period, electronegativity decreases as the atomic number increases.
Which of these statement(s) is/are correct ?
(a) I only
(b) II only
(c) I and III
(d) II and III
239: Which one of the following bodies finalises the Five-Year Plans proposals?
(a) Planning Commission
(b) Union Cabinet
(c) National Development Council
(d) Ministry of Planning
240: There are three drawers in a table. One contains two gold coins, another two silver coins, and the third, a silver coin and a gold coin. One of the drawers is pulled out and a coin is taken out. It turns out to be a silver coin. What is the probability of drawing a gold coin, if one of the other two drawers is pulled out next and one of the coins in it is drawn at random ?
(a) 37.5%
(b) 50%
(c) 62.5%
(d) 75%