Arrange Given Rational Numbers In Descending Order 5 8 13 16 And 7 12

Arrange the given rational numbers in descending order: (i) 5/8, 13/(-16) and (-7)/12 (ii) 3/(-10), (-13)/30 and 8/(-20)

Answers:

(i) 5/8, 13/(-16) and (-7)/12

= 5/8, (-13)/16 and (-7)/12

= (5 × 6)/(8 × 6), (-13 × 3)/(16 × 3) and (-7 × 4)/(12 × 4)      (∵  LCM of  8, 16 and 12 = 48)

= 30/48, (-39)/48 and (-28)/48

Since, 30 > -28 > -39

∴   30/48 > (-28)/48 > (-39)/48

⇒ 5/8 > (-7)/12 > (-13)/16

(ii) 3/(-10), (-13)/30 and 8/(-20)

= (-3)/10, (-13)/30 and (-8)/20

= (-3 × 6)/(10 × 6), (-13 × 2)/(30 × 2) and (-8 × 3)/(20 × 3)     (∵   LCM  of 10, 20 and 30 = 60)

= (-18/60), (-26)/60 and (-24)/60

Since, -18 > – 24 > – 26

∴ (-18)/60 > (-24)/60 > (-26)/60

⇒  (-3)/10 > (-8)/20 > (-13)/30