Question

pls answer theses question​

Answer 1

Answer

21 . (-18)-(-15)+(-4)-(+9)

-18 +15 -4 -9

-31 + 15

-16

22 . Descending order 11 /9 , 8/9 ,7/9 ,4/9 ,2/9

23 . edges 6

faces 9

24 .a) 125×8×25×40

1000×1000

1000000

b)8×291×125

8×125×291

1000×291

291000

25. a) PC

b) BO , AO , PO , CO

26 .Least number when divided by 12,16,24,36 and leaves remainder 0

LCM of 12,16,24,36

So,LCM leaves remainder 0

So,Required number will be 7 more than LCM

∴ Required number=LCM+7

Factors of 12=2×3×2

Factors of 16=2×2×2×2

Factors of 24=2×2×2×3

Factors of 36=2×2×3×3

∴ LCM=2×2×2×2×3×3=16×9=144

So,Required number=LCM+7=144+7=151

First five multiple of 12

12 , 24 ,36 , 48, 60

first five multiple of 16

16, 32, 48 ,64 ,80

first five multiple of 24

24, 48. ,72, 96, 120

first five multiple of 36

36, 72, 108 ,144, 180