Exercise 3D
Question 1
Convert
(i) 8 km to m
=8×1000 m
=8000 m
(ii) 4.8 hg to cg
=4.8×10000 cg
=48000 cg
(iii) 18.5 L to ml
=18.5×1000
=18500 ml
(iv) 23.35 dl to cl
=28.35×10 cl
=283.5 cl
(v) 93 dag to dg
=93×100 dg
=9300 dg
(vi) 29.83 hm to m
=29.83×100 m
=2983 m
(vii) 9600 mm to m
$=9600 \times \frac{1}{1000}$ m
=9.6 m
(viii) 32.48 dag to kg
$=32.48 \times \frac{1}{100}$
=0.3248 kg
(ix) 125 cm to dam
$=125 \times \frac{1}{1000}$
=0.125 dam
(x) 292 ml to cl
$=292 \times \frac{1}{10}$
=29.2 cl
(xi) 179.6 dg to hg
$=179.6 \times \frac{1}{1000}$
=0.1796 hg
(xii) 0.85 dal to cl
=0.85×1000 cl
=850 cl
(xiii) 750 m to km
$=750 \times \frac{1}{1000}$
=0.75 km
(xiv) 1600 ml to l
$=1600 \times \frac{1}{1000}$
=1.6 l
(xv) 8.75 kg to g
=8.75×1000 g
=8750 g
Question 2
Convert :
(i) 46 m 18 cm to cm
=46×100 cm + 18 cm
=4600 cm + 18 cm
=4618 cm
(ii) 1 kg 2g to g
=1×1000 g + 2 g
=1000 g + 2g
=1002 g
(iii) 6 km 350 m to m
=6×1000 m + 350 m
=6000 m + 350 m
=6350 m
(iv) 3749 m to km and m
=3000 m + 749 m
$=3000 \times \frac{1}{1000}$ km + 749 m
=3 km 749 m
(v) 349 cl to l and cl
= 300 cl + 49 cl
$=300 \times \frac{1}{100}$ l + 49 cl
=3 l 49 cl
(vi) 5003 g to kg and g
= 5000 g + 3 g
$=5000 \times \frac{1}{1000}$ kg + 3 g
=5 kg 3 g
(vii) 6095 mg to g and mg
= 6000 mg + 9 5 mg
$=6000 \times \frac{1}{1000}$g+95 mg
=6g 95 mg
(viii) 2302 cm to m and cm
=2300 cm + 2 cm
$=2300 \times \frac{1}{100}$ m + 2 cm
=23 m 2 cm
(ix) 18 km 5 m to m
=18×1000 m + 5 m
=18000 m + 5 m
=18005 m
(x) 5 kl 250 l to l
=5000 l + 250 l
=5250 l
Question 3
The Mariana Trench is about 10,900 m deep in the pacific Ocean . Is this greater or less than 8.85 km height of Mt.Everest.
Sol :
Mariana Trench is greater because height of Mt.Everest 8.85×100 m=8850 m
=10900-8850
=2050 m greater
Question 4
The thickness of 54 sheets of paper is 15.12 mm.What is the thickness of each sheet in cm?
Sol :
15.12 mm into cm $=15.12 \times \frac{1}{10}$ cm
=1.512 cm
Thickness of 54 sheets=1.512 cm
Thickness of 1 sheet$=\frac{1.512}{54}$
=0.028 cm
Question 5
An inch contains 2.54 cm. How many cm will be in 12.5 inches?
Sol :
If 1 inch contains 2.54 cm
∵cm in 12.5 inches=2.54×12.5
=31.75 cm
Question 6
Gauri spends 0.75 of her salary every month. If she earns 12000 per month in how many month will she save 39000 ?
Sol :
Gauri Save=1-0.75
=0.25 of the salary
=0.25×1200=3000
Gauri save 3000 per month
∴She will save 3900 in $=\frac{39000}{3000}$=13 month
Question 7
How many jars each holding 1.75 kg of jam can be filled from a vessel containing 100 kg of jam and how much remains?
Sol :
Each jars contains=1.75 kg jam
So from 100 kg vessel fill $=\frac{100}{1.75}=\frac{100 \times 100}{1.75}$
$=\frac{400}{7}$
=57 jars will filled
and $\frac{1}{7}$ of 1.75 is left remains
