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: D) 72 Explanation: If number of visitors on 1st, 2nd, 3rd, 4th & 5th day are k, l, m, n & o respectively, thenk + l + m + n = 58 x 4 = 232 ---- (i) & l + m + n + o = 60 x 4 = 240 ---- (ii)Subtracting (i) from (ii), we get o-k = 8 ---(iii)Given, k/o = 8/9 ----(iv)So from (iii) & (iv), we geta = 64, e = 72Therefore, number of visitors on 5th day is 72.

1. Answer : 2 Explanation : Productivity = Total production/area of Agr.land  Productivity of UP = [ (35000+30000+25000) / (30/100) ] = 300000   Productivity of MP = [ (30000+37500+27500) / (25/100) ] = 380000   Productivity of Bihar = [ (22500+27500+25000) / (20/100) ] = 375000  Productivity of Odisha = [ (22500+15000+10000) / (5/100) ]= 950000   Productivity of Haryana = [ (30000+25000+35000) / (8/100) ] = 1125000   Productivity of Punjab = [ (40000+35000+30000) / (12/100) ] = 875000  The Productivity of Haryana is the maximum.       2. Answer : 5   Explanation : Production of Punjab is maximum = 105000 tonnes      3. Answer : 3  Explanation : Production of Wheat in Punjab = 40000 tones Production of Maize in Odisha = 10000 tones Required % = (40000 - 10000)/100 = 300%      4. Answer : 4  Explanation : The ratio of prodution of Rice in Bihar to the production of Wheat in Haryana = 25000 tonnes : 25000 tonnes = 1 : 1       5. Answer : 1   Explanation : Income of MP from export of 40% of Rice at the rate of Rs.30 per kg = Rs.39crore Income of UP from export of 30% of Rice at the rate of Rs.32 per kg = Rs.28.8 crore  Required ratio = 39 : 28.8 = 390 : 288 = 65 : 48

Answer: B) Magnetic north Explanation: Wherever on earth we hold a compass, the needle points towards the magnetic North Pole. A compass is a great tool for navigation. Compass is widely used in aircrafts, ships, military services,...

Answer: A) NH-1 Explanation: N.H. 1 is also called The Sher Shah Suri Marg between Delhi and Amritsar.

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: C) Helioseismology Explanation: Helioseismology is the study of the solar interior using observations of waves on the Sun's surface. It has done much to improve our understanding of the interior of the Sun, testing the physical inputs used to model stellar interiors and providing a detailed map of the Sun's structure and internal rotation.

Answer: C) 180º Explanation: Angle traced by the hour hand in 6 hours =360o12×6 = 180o.