LCM for 15 and 30

The first method to find LCM for numbers 15 and 30 is to find Greatest Common Factor (GCF) of these numbers. Here's the formula:

LCM = (Number1 × Number2) ÷ GCF

GCF of numbers 15 and 30 is 15, so

LCM = (15 × 30) ÷ 15

LCM = 450 ÷ 15

LCM = 30

The second method to find LCM for numbers 15 and 30 is to list out the common multiples for both nubmers and pick the first which matching:

Multiples of 15: 15, 30, 45, 60

Multiples of 30: 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360, 390, 420, 450, 480, 510, 540, 570, 600, 630, 660, 690, 720, 750, 780, 810, 840, 870, 900, 930, 960, 990, 1020, 1050, 1080, 1110, 1140, 1170, 1200, 1230, 1260, 1290, 1320, 1350, 1380, 1410, 1440, 1470, 1500, 1530, 1560, 1590, 1620, 1650, 1680, 1710, 1740, 1770, 1800, 1830, 1860, 1890, 1920, 1950, 1980, 2010, 2040, 2070, 2100, 2130, 2160, 2190, 2220, 2250, 2280, 2310, 2340, 2370, 2400, 2430, 2460, 2490, 2520, 2550, 2580, 2610, 2640, 2670, 2700, 2730, 2760, 2790, 2820, 2850, 2880, 2910, 2940, 2970, 3000, 3030, 3060, 3090, 3120, 3150, 3180, 3210, 3240, 3270, 3300, 3330, 3360, 3390, 3420, 3450, 3480, 3510, 3540, 3570, 3600, 3630, 3660, 3690, 3720, 3750, 3780, 3810, 3840, 3870, 3900, 3930, 3960, 3990, 4020, 4050, 4080, 4110, 4140, 4170, 4200, 4230, 4260, 4290, 4320, 4350, 4380, 4410, 4440, 4470, 4500, 4530, 4560, 4590, 4620, 4650, 4680, 4710, 4740, 4770, 4800, 4830, 4860, 4890, 4920, 4950, 4980, 5010, 5040, 5070, 5100, 5130, 5160, 5190, 5220, 5250, 5280, 5310, 5340, 5370, 5400, 5430, 5460, 5490, 5520, 5550, 5580, 5610, 5640, 5670, 5700, 5730, 5760, 5790, 5820, 5850, 5880, 5910, 5940, 5970, 6000, 6030, 6060, 6090, 6120, 6150, 6180, 6210, 6240, 6270, 6300, 6330, 6360, 6390, 6420, 6450, 6480, 6510, 6540, 6570, 6600, 6630, 6660, 6690, 6720, 6750, 6780, 6810, 6840, 6870, 6900, 6930, 6960, 6990, 7020, 7050, 7080, 7110, 7140, 7170, 7200, 7230, 7260, 7290, 7320, 7350, 7380, 7410, 7440, 7470, 7500, 7530, 7560, 7590, 7620, 7650, 7680, 7710, 7740, 7770, 7800, 7830, 7860, 7890, 7920, 7950, 7980, 8010, 8040, 8070, 8100, 8130, 8160, 8190, 8220, 8250, 8280, 8310, 8340, 8370, 8400, 8430, 8460, 8490, 8520, 8550, 8580, 8610, 8640, 8670, 8700, 8730, 8760, 8790, 8820, 8850, 8880, 8910, 8940, 8970, 9000, 9030, 9060, 9090, 9120, 9150, 9180, 9210, 9240, 9270, 9300, 9330, 9360, 9390, 9420, 9450, 9480, 9510, 9540, 9570, 9600, 9630, 9660, 9690, 9720, 9750, 9780, 9810, 9840, 9870, 9900, 9930, 9960, 9990, 10020, 10050, 10080, 10110, 10140, 10170, 10200, 10230, 10260, 10290, 10320, 10350, 10380, 10410, 10440, 10470, 10500, 10530, 10560, 10590, 10620, 10650, 10680, 10710, 10740, 10770, 10800, 10830, 10860, 10890, 10920, 10950, 10980, 11010, 11040, 11070, 11100, 11130, 11160, 11190, 11220, 11250, 11280, 11310, 11340, 11370, 11400, 11430, 11460, 11490, 11520, 11550, 11580, 11610, 11640, 11670, 11700, 11730, 11760, 11790, 11820, 11850, 11880, 11910, 11940, 11970, 12000, 12030, 12060, 12090, 12120, 12150, 12180, 12210, 12240, 12270, 12300, 12330, 12360, 12390, 12420, 12450, 12480, 12510, 12540, 12570, 12600, 12630, 12660, 12690, 12720, 12750, 12780, 12810, 12840, 12870, 12900, 12930, 12960, 12990, 13020, 13050, 13080, 13110, 13140, 13170, 13200, 13230, 13260, 13290, 13320, 13350, 13380, 13410, 13440, 13470, 13500, 13530, 13560, 13590, 13620, 13650, 13680, 13710, 13740, 13770, 13800, 13830, 13860, 13890, 13920, 13950, 13980, 14010, 14040, 14070, 14100, 14130, 14160, 14190, 14220, 14250, 14280, 14310, 14340, 14370, 14400, 14430, 14460, 14490, 14520, 14550, 14580, 14610, 14640, 14670, 14700, 14730, 14760, 14790, 14820, 14850, 14880, 14910, 14940, 14970, 15000, 15030, 15060, 15090, 15120, 15150, 15180, 15210, 15240, 15270, 15300, 15330, 15360, 15390, 15420, 15450, 15480, 15510, 15540, 15570, 15600, 15630, 15660, 15690, 15720, 15750, 15780, 15810, 15840, 15870, 15900, 15930, 15960, 15990, 16020, 16050, 16080, 16110, 16140, 16170, 16200, 16230, 16260, 16290, 16320, 16350, 16380, 16410, 16440, 16470, 16500, 16530, 16560, 16590, 16620, 16650, 16680, 16710, 16740, 16770, 16800, 16830, 16860, 16890, 16920, 16950, 16980, 17010, 17040, 17070, 17100, 17130, 17160, 17190, 17220, 17250, 17280, 17310, 17340, 17370, 17400, 17430, 17460, 17490, 17520, 17550, 17580, 17610, 17640, 17670, 17700, 17730, 17760, 17790, 17820, 17850, 17880, 17910, 17940, 17970, 18000, 18030, 18060, 18090, 18120, 18150, 18180, 18210, 18240, 18270, 18300, 18330, 18360, 18390, 18420, 18450, 18480, 18510, 18540, 18570, 18600, 18630, 18660, 18690, 18720, 18750, 18780, 18810, 18840, 18870, 18900, 18930, 18960, 18990, 19020, 19050, 19080, 19110, 19140, 19170, 19200, 19230, 19260, 19290, 19320, 19350, 19380, 19410, 19440, 19470, 19500, 19530, 19560, 19590, 19620, 19650, 19680, 19710, 19740, 19770, 19800, 19830, 19860, 19890, 19920, 19950, 19980, 20010, 20040, 20070, 20100, 20130, 20160, 20190, 20220, 20250, 20280, 20310, 20340, 20370, 20400, 20430, 20460, 20490, 20520, 20550, 20580, 20610, 20640, 20670, 20700, 20730, 20760, 20790, 20820, 20850, 20880, 20910, 20940, 20970, 21000, 21030, 21060, 21090, 21120, 21150, 21180, 21210, 21240, 21270, 21300, 21330, 21360, 21390, 21420, 21450, 21480, 21510, 21540, 21570, 21600, 21630, 21660, 21690, 21720, 21750, 21780, 21810, 21840, 21870, 21900, 21930, 21960, 21990, 22020, 22050, 22080, 22110, 22140, 22170, 22200, 22230, 22260, 22290, 22320, 22350, 22380, 22410, 22440, 22470, 22500, 22530, 22560, 22590, 22620, 22650, 22680, 22710, 22740, 22770, 22800, 22830, 22860, 22890, 22920, 22950, 22980, 23010, 23040, 23070, 23100, 23130, 23160, 23190, 23220, 23250, 23280, 23310, 23340, 23370, 23400, 23430, 23460, 23490, 23520, 23550, 23580, 23610, 23640, 23670, 23700, 23730, 23760, 23790, 23820, 23850, 23880, 23910, 23940, 23970, 24000, 24030, 24060, 24090, 24120, 24150, 24180, 24210, 24240, 24270, 24300, 24330, 24360, 24390, 24420, 24450, 24480, 24510, 24540, 24570, 24600, 24630, 24660, 24690, 24720, 24750, 24780, 24810, 24840, 24870, 24900, 24930, 24960, 24990, 25020, 25050, 25080, 25110, 25140, 25170, 25200, 25230, 25260, 25290, 25320, 25350, 25380, 25410, 25440, 25470, 25500, 25530, 25560, 25590, 25620, 25650, 25680, 25710, 25740, 25770, 25800, 25830, 25860, 25890, 25920, 25950, 25980, 26010, 26040, 26070, 26100, 26130, 26160, 26190, 26220, 26250, 26280, 26310, 26340, 26370, 26400, 26430, 26460, 26490, 26520, 26550, 26580, 26610, 26640, 26670, 26700, 26730, 26760, 26790, 26820, 26850, 26880, 26910, 26940, 26970, 27000, 27030, 27060, 27090, 27120, 27150, 27180, 27210, 27240, 27270, 27300, 27330, 27360, 27390, 27420, 27450, 27480, 27510, 27540, 27570, 27600, 27630, 27660, 27690, 27720, 27750, 27780, 27810, 27840, 27870, 27900, 27930, 27960, 27990, 28020, 28050, 28080, 28110, 28140, 28170, 28200, 28230, 28260, 28290, 28320, 28350, 28380, 28410, 28440, 28470, 28500, 28530, 28560, 28590, 28620, 28650, 28680, 28710, 28740, 28770, 28800, 28830, 28860, 28890, 28920, 28950, 28980, 29010, 29040, 29070, 29100, 29130, 29160, 29190, 29220, 29250, 29280, 29310, 29340, 29370, 29400, 29430, 29460, 29490, 29520, 29550, 29580, 29610, 29640, 29670, 29700, 29730, 29760, 29790, 29820, 29850, 29880, 29910, 29940, 29970, 30000, [...], 30

So the LCM for 15 and 30 is 30

Another method to find LCM for numbers 15 and 30 is to list all Prime Factors for both numbers and multiply the highest exponent prime factors: