120km
165km
195km
(150 + 45√3)km
240km
Correct answer is C
No explanation has been provided for this answer.
Which of the following factors is not associated with aquatic habitats?
Temperature
Light intensity
Humidity
Turbidity
Wave action
Correct answer is C
Humidity
State the fifth and seventh terms of the sequence \(-2, -3, -4\frac{1}{2}, ...\)
\(-\frac{81}{8}, -\frac{729}{32}\)
\(\frac{8}{81}, \frac{72}{39}\)
\(\frac{27}{729}, \frac{718}{39}\)
\(-\frac{27}{16}, -\frac{79}{81}\)
\(-\frac{21}{8}, \frac{32}{618}\)
Correct answer is A
\(-2, -3, -4\frac{1}{2}, ...\)
This is a G.P with r = 1\(\frac{1}{2}\).
\(T_{n} = ar^{n - 1}\) (terms of a G.P)
\(T_{5} = (-2)(\frac{3}{2})^{5 - 1}\)
= \(-2 \times \frac{81}{16}\)
= \(-\frac{81}{8}\)
\(T_{7} = (-2)(\frac{3}{2})^{7 - 1}\)
= \(-2 \times \frac{729}{64}\)
= \(-\frac{729}{32}\)
Which of the following is not a safety precaution in a nuclear station?
Radioactive materials are stored in glass casings
Radioactive materials are handled with remote-controlled tongs
Technicians in nuclear stations wear radio-sensitive badges which are checked regularly.
Technicians in nuclear stations wear radio-sensitive badges which are checked regularly.
Correct answer is B
No explanation has been provided for this answer.
Which of the following is not a way to reduce air pollution?
Siting factories and power stations away from residential areas
Building tall factory chimneys
Passing waste gases through filters and absorbers
Using lead-free petrol in cars
Recycling tins, cans, and bottles
Correct answer is B
No explanation has been provided for this answer.