1386: Electrically charged particles from space travelling at speeds of several hundred km/sec can severely harm living beings if they reach the surface of the Earth. What prevents them from reaching the surface of the Earth?
(a) The Earth's magnetic field diverts them towards its poles
(b) Ozone layer around the Earth reflects them back to outer space
(c) Moisture in the upper layers of atmosphere prevents them from reaching the surface of the Earth
(d) None of the statements (a), (b) and (c) given above is correct
1387: The chemical used as a 'fixer' in photography is
(a) sodium sulphate
(b) sodium thiosulphate
(c) ammonium persulphate
(d) borax
1388: In a town 25% families own a phone and 15% own a car. 65% families own neither a phone nor a car. 2000 families own both a car and a phone.
Consider the following statements in this regard:
I. 10% families own both a car and a phone.
II. 35% families own either a car or a phone.
III. 40,000 families live in the town.
Which of the above statements are correct ?
(a) I and II
(b) I and III
(c) II and III
(d) I, II and III
1389: How many numbers from 0 to 999 are not divisible by either 5 or 7 ?
(A) 313
(B) 686
(C) 341
(D) 786
1390: The time in the wall-clock is 3.25 the acute angle between the hours-hand and the minutes-hand is
(a) 60°
(b) 52 ½°
(c) 47 ½°
(d) 42°