19921.simplify: 2.$\sqrt[3]{40}$+3.\sqrt[3]{625}$-4.\sqrt[3]{320}$
16.$\sqrt[3]{2}$
5.$\sqrt[3]{3}$
3. $\sqrt[3]{5}$
3.$\sqrt[3]{4}$
19924.A sector containing an angle of 240° is cut off from a circle of radius 42 cm and folded into a cone, then the curved surface area of the cone is
4624 cm$^{2}$
3696 cm$^{2}$
6369 cm$^{2}$
6639 cm$^{2}$
19926.Eight men working 9 hours a day can do a piece of work in 28 days. In how many days will 12 men working for 7 hours a day do the same work?
20 days
18 days
28 days
24 days
19928.The largest of 100 measurements is 3.84 kg. If the range is 2.46 kg, then the Smallest measurement is
1.38 kg
3,38 kg
2.38 kg
6.30 kg
19930.The measures of the angles of a triangle are in the ratio 2:4: 6, then the angles of the triangle are
30°, 60°,90°
20°, 70°,90°
40°, 60°, 80°
26°, 58°, 96°
19932.If x = 2 + $\sqrt{3}$, then the value of $x^{2}$ - $\dfrac{1}{x^{2}}$ Χ
14
8$\sqrt{3}$
4 $\sqrt{3}$
0
19934.The distance between two places is 61 km. If a two wheeler takes hours to cross the distance, then what is the speed of the two wheeler?
25 km
40 km
35 km
20 km
19936.The next number of the sequence
1, 2, 5, 6, 14, 24, 30, 120, ............
1, 2, 5, 6, 14, 24, 30, 120, ............
91
55
720
none of these
19938.$\dfrac{4}{5}$ + $\dfrac{7}{2} \div$ ($\dfrac{5}{2}$ - $\dfrac{3}{4}$) $\times$ $\dfrac{7}{8}$ is equal to
1$\dfrac{1}{20}$
3$\dfrac{5}{20}$
2$\dfrac{11}{20}$
5$\dfrac{1}{20}$