[PPSC Scientific Officer (Cyber Forensics, 2023)]
6. A, B and C can walk at the rates of 3, 4 and 5 km an hour respectively. They start from Poona at 1, 2, 3 o’clock respectively. When B catches A, B sends him back with a message to C. When will C get the message?
5.15
5.20
5.30
6.00
7. A worldwide ban on the production of certain ozone-destroying chemicals would provide only an illusion of protection. Quantities of such chemicals, already produced, exist as coolants in millions of refrigerators. When they reach the ozone layer in the atmosphere, their action cannot be halted. So, there is no way to prevent these chemicals from damaging the ozone layer further. Which of the following, if true, most seriously weakens the argument above?
In modern societies, refrigeration of food is necessary to prevent unhealthy and potentially life-threatening conditions
Replacement chemicals that will not destroy ozone have not yet been developed and would be more expensive than the chemicals now used as coolants in refrigerators
Even if people should give up the use of refrigerators, the coolants already in existing refrigerators are a threat to atmospheric ozone.
The coolants in refrigerators can be fully recovered at the end of the useful life of the refrigerators and reused
8. Vertices of a quadrilateral ABCD are A(0, 0), B(4, 5), C(9, 9) and D(5, 4). What is the shape of the quadrilateral?
square
rectangle (not square)
rhombus
parallelogram (not rhombus)
9. A merchant has 100 kgs of rice, part of which he sells at 7% profit and the rest at 17% profit. He gains 10% on the whole. Find how much is sold at 7% profit?
50kgs
70kgs
40kgs
30kgs
10. If x, y and z are non-zero numbers such that 1 ≥ y > x and xy = z, which of the following CANNOT be true?
y > z
y = z
z = x
x > z