18. total no fo districts in all states and their population

Map key	Name of State or Union Territory (Italicized)	Number of Districts	Population[4]	Population/district
1	Andhra Pradesh	13	49,386,799	3,798,985
2	Arunachal Pradesh	25	1,383,727	57,656
3	Assam	33	31,169,272	944,523
4	Bihar	38	104,099,452	2,739,459
5	Chhattisgarh	27	25,545,198	946,118
6	Goa	2	1,458,545	729,273
7	Gujarat	33	60,439,692	1,831,506
8	Haryana	22	25,351,462	1,152,339
9	Himachal Pradesh	12	6,864,602	572,050
10	Jharkhand	24	32,988,134	1,374,506
11	Karnataka	30	61,095,297	2,036,510
12	Kerala	14	33,406,061	2,386,147
13	Madhya Pradesh	52	72,626,809	1,396,669
14	Maharashtra	36	112,374,333	3,121,509
15	Manipur	16	2,721,756	170,110
16	Meghalaya	11	2,966,889	269,717
17	Mizoram	8	1,097,206	137,151
18	Nagaland	12	1,978,502	179,864
19	Odisha	30	41,974,218	1,399,141
20	Punjab	22	27,743,338	1,261,061
21	Rajasthan	33	68,548,437	2,077,225
22	Sikkim	4	610,577	152,644
23	Tamil Nadu	37	72,147,030	2,254,595
24	Telangana	33	35,193,978	1,135,290
25	Tripura	8	3,673,917	459,240
26	Uttar Pradesh	75	199,812,341	2,664,165
27	Uttarakhand	13	10,086,292	775,869
28	West Bengal	23	91,276,115	3,968,527

17.Solar System EXPLANATION

16. 10 largest countries in world

	Country	Area (Km²)	Area (mi²)	% of world landmass
1	Russia	16,376,870	6,323,142	11.0 %
2	China	9,388,211	3,624,807	6.3 %
3	United States	9,147,420	3,531,837	6.1 %
4	Canada	9,093,510	3,511,022	6.1 %
5	Brazil	8,358,140	3,227,095	5.6 %
6	Australia	7,682,300	2,966,151	5.2 %
7	India	2,973,190	1,147,955	2.0 %
8	Argentina	2,736,690	1,056,641	1.8 %
9	Kazakhstan	2,699,700	1,042,360	1.8 %
10	Algeria	2,381,740	919,595	1.6 %

15. longest rivers in world

River Name	Location	Length (miles approx)	Length (km approx)	Drainage Area (sq miles)	Flow at mouth (cubic m per second)
Nile	Africa	4,160	6,695	1,170,000	1,584
Amazon	South America	4,000	6,400	2,270,000	180,000
Yangtze	Asia (China)	3,900	6,240	698,000	35,000
Mississippi	USA	3,870	6,192	1,247,000	17,545
Ob	Asia (Russia)	3,459	5,534	1,154,000	12,600
Yenisei/ Angara	Asia (Russia)	3,440	5,504	996,000	19,600
Yellow River	Asia (China)	3,440	5,504	290,000	1,365
Congo	Africa (Zaire)	2,900	4,640	1,440,000	42,000
Amur	Asia	2,800	4,480	730,000	12,500
Parana	Uruguay	2,795	4,472	1,197,000	19,500
Lena	Asia (Russia)	2,700	4,320	961,000	16,400
Mackenzie	North America	2,640	4,224	697,000	7,500
Niger	Africa	2,600	4,160	850,000	5,700
Mekong	Asia	2,500	4,000	750,000	15,900
Volga	Europe	2,300	3,680	533,000	8,000
Murray-Darling	Australia	2,300	3,680	410,000	391
Rio-Grande	USA	1,885	3,016	310,000	82