16.
4.
The first 20 odd numbers are: 13579111315171921232527293133353739.
9801 * The sum of the first two odd numbers (1+3) is 4, or 22 * The sum of the first three odd numbers (1+3+5) is 9, or 32 * The sum of the first four odd numbers (1+3+5+7) is 16, or 42 * ...and so on So the sum of the first 99 odd numbers, using the pattern above, would be 992 or 9801.
The first 100 odd whole numbers are: 13579111315171921232527293133353739414345474951535557596163656769717375777981838587899193959799101103105107109111113115117119121123125127129131133135137139141143145147149151153155157159161163165167169171173175177179181183185187189191193195197199.
The first 85 odd numbers are: 1 3579111315171921232527293133353739414345474951535557596163656769717375777981838587899193959799101103105107109111113115117119121123125127129131133135137139141143145147149151153155157159161163165167169.
No odd numbers are multiples of 4.
The sum of the first 15 odd numbers is 225.
The sum of the first 100 odd numbers is 10,000.
The sum of the first 300 odd numbers is 90,000
The sum of the first 40 odd numbers is 1,600.
The sum of the first 600 odd numbers is 360,000.