Answer: A) 3, 3, 8 Explanation: Let’s break it down. The product of their ages is 72. So what are the possible choices?   2, 2, 18 – sum(2, 2, 18) = 222, 4, 9 – sum(2, 4, 9) = 152, 6, 6 – sum(2, 6, 6) = 142, 3, 12 – sum(2, 3, 12) = 173, 4, 6 – sum(3, 4, 6) = 133, 3, 8 – sum(3, 3, 8 ) = 141, 8, 9 – sum(1,8,9) = 181, 3, 24 – sum(1, 3, 24) = 281, 4, 18 – sum(1, 4, 18) = 231, 2, 36 – sum(1, 2, 36) = 391, 6, 12 – sum(1, 6, 12) = 19   The sum of their ages is the same as your birth date. That could be anything from 1 to 31 but the fact that Jack was unable to find out the ages, it means there are two or more combinations with the same sum. From the choices above, only two of them are possible now.   2, 6, 6 – sum(2, 6, 6) = 143, 3, 8 – sum(3, 3, 8 ) = 14   Since the eldest kid is taking piano lessons, we can eliminate combination 1 since there are two eldest ones. The answer is 3, 3 and 8.

Answer: C) 8 Explanation: Let the number of boys = x From the given data, => [21x + 16(18)]/(x+16) = 19 => 21x - 19x = 19(16) - 16(18) => 2x = 16 => x = 8 Therefore, the number of boys in the class = 8.

Answer: C) 15 days Explanation: We know that Time is inversely proportional to Efficiency Here given time ratio of P & P+Q as P/P+Q = 150/100 = 3:2 Efficiency ratio of P & Q as P:Q = 2:1 ....(1) Given Efficiency ratio of Q & R as Q:R = 3:1 ....(2) From (1) & (2), we get P:Q:R = 6:3:1 P alone can finish the work in 22.5(3+1)/6 = 15 days.

Answer: D) 4 3/8 km Explanation: Relative Speed = 5 ¾ - 4 ½ = 1 ¼ Time = 3 ½ h. Distance = 5/4 x 7/2 = 35/8 = 4 3/8 km.

Answer: B) Jameeyat Riya Mame Nizam Explanation:

Emergence of two great power blocs: Two power blocs came into existence after the Second World War. The United States of America and Soviet Russia became two Super Powers. They tried to dominate over other countries in their own way. Ultimately, it gave a headache to the world.   The Cold War was a state of political and military tension after World War II between powers in the Western Bloc (the United States, its NATO allies and others) and powers in the Eastern Bloc (the Soviet Union and its allies in the Warsaw Pact).

Answer: A) Vacuum Explanation: A Sound wave needs a medium for propogation. Hence, Sound cannot travel through a vacuum. A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibrations to work in.

Answer: A) Capillary action phenomenon Explanation: Blotting paper absorbs ink by the process of capillary action. The capillary action is based on the property of surface tension of liquid.   All unsized paper will absorb water. Blotting paper is not sized and made bulkier to provide capillary action for faster absorption of liquid.   Blotting paper has also been sold as a cosmetic to aid in the removal of skin oils and makeup.