NCTB Class 7 Math Chapter Three Exercise 3 Solution by Math Expert. Bangladesh Board Class 7 Math Solution Chapter 3 “Measurement” Exercise 3 Solution.
|
Board |
NCTB |
|
Class |
7 |
| Subject |
Math |
|
Chapter |
3 |
|
Chapter Name |
“Measurement” |
| Exercise |
3 Solution |
Exercise:- 3
(1) Solution:- 1sq.foot = (c) 929sqcm.
(2) Solution:- If the length of one edge of a cube is 3m then total surface area of the cube – (a) 5sqm.
Therefore, Area of one surface= (3×3) = 9sqm.
Therefore, Total area= (6×9) = 9sqm.
(3) Solution:- Let, breadth of garden = x m.
Therefore, length of garden= 3x m.
Therefore, 2 (3x+x) = 400
=> 4x = 200
=> x = 200/4
= 50
Therefore, Breadth = 50m.
Length= (3×50)m
= 150m (c)
(4) Solution:- Area = (150×50)sqm
(d) = 7500sqm.
(5) Solution:- meaning of deci in Latin – (b) One tenth.
(6) solution:- Perimeter of land = 2 (20+15)
= (b) 70m.
(7) solution:– Without work way, length of land
= {20 – (2+2)}m
= 16m.
Breadth of land
= {15- (2+2)}
= 11m.
Therefore, Area= (16×11) sqm
= 176sqm.
(8) (a) Solution:- 40390cm= 0.4039km.
(8) (b) Solution:- 75m 250mm
= 75m+ 250mm
= 75m+ 250/100m [Because, 1m= 1000mm]
= 75+0.5
= 75025m
= 75.25/1000
= 0.07525km.
(9) Solution:- 5.37 decimetre = (5.37x 10)m
= 53.4m
Therefore, 1m= 10decm.
Therefore, 53.7m = 537decm.
(10) (a) Solution:- Area of triangle
= ½ x .10x 6
= 30sqm.
(10) (b) Solution:- Area of triangle
= ½ x 25x14cm.
= 175sqcm.
(11) Solution:- Let, breadth of a rectangular plot x m. and length = 3x m.
Therefore, perimeter= 2 (3x+x)
= 2x4x
= 8x m.
Therefore, 8x= 1000
=> x= 1000/8
X = 125
Therefore, breadth= 125m.
Therefore, length= (3×125)m.
= 375m.
Therefore, length 375m and breadth 125m.
(12) Solution:– Perimeter of rectangular park
= 2 ( l+ b)
= 2 (100+50)m.
= (2×150)m.
= 300m.
Therefore, 1m cost to fencing is 100TK.
Therefore, 300m cost to fencing in (300×100) TK.
= 30000TK.
(13) Solution:- Given, base of parallelogram = 40m
Therefore, height of parallelogram = 50m.
Therefore, Area= (40×50) = 2000sqm.
(14) Solution:- Area of cube = (4x40sqm
= 16sqm.
Therefore, Total surface area of cube
= (16×6)
= 96sqm.
(15) Solution:- Produces potatoes
= 500kg 700gm
= (500×1000) + 700gm
= 5007000gm.
Joseph, 1 piece of land produces 500 700gm potatoes.
Therefore, 11 piece of land produces (11×500 700) Gm potatoes
= 5507700gm
= 5507000+7.00gm
= 5507000/1000+ 7000gm
= (5507kg+700gm)
(16) Solution:- In 16 area land produces 28 metric ton paddy
Therefore, 1 area land produces 28/16 metric ton paddy.
= 7/4 metric ton paddy.
= 1 – ¾ metric ton.
(17) Solution:- 1 month = 30days.
In 30 days produces rod = 200000m.t.
Therefore, 1 days produces rod = 200000/30 m.t
= 666 – 2/3m.t
= 666m.ton + 2/3x 1000kg
= 666m.ton +666- 2/3kg
= 666m.ton+666kg +2/3x 1000gm
= 666m.ton+ 666kg+666-2/3gm.
(18) Solution:- In 1 day sell 20kg 400gm.
= 20 400gm.
Therefore, in 30 day sell = (20400×30) gm
= 612 000gm
= 612kg.
(19) Solution:- in 1 piece of land produces 20 kg 850gm mustard = 20850gmmustard.
Therefore, in 7 piece of land produces = (20850×7) mustard.
= 145950gm.
= (145000+950)gm.
= 145kg 950gm.
(20) Solution:- Volume of mug = 1500cu.cm.
= 1500/1000 list
= 1.5 lit.
Therefore, 1.5 lit in 1 mug
Therefore, 1 lit in 1/1.5 mug
Therefore, 270 lit in 270/1.5 mug
= 180mug.
(22) Solution:- In 1 day requires milk 125 lit
Therefore, 30 day requires mil (30×1.255) lit
= 37.50lit.
Now, 1 lit of milk cost 52TK.
Therefore, 37.50 lit of milk cost (37.50×52) TK.
= 1650TK.
(23) Solution:-
(24) Solution:- Let, the breadth of room X m.
Therefore, length = (3xx) 3xm.
Therefore, area = (3Xx) sqm.
= 3x2sqm.
Therefore, 7.50TK – 1 sqm.
1TK. — 1/7.50 sqm.
Therefore, 1102.50TK. – 1×1102.50/7.50 sqm
= 147sqm.
Therefore, Area of room 147sqm
Therefore, 3x2 = 147
=> x2 = 147/3
= 49
=> x = √49
= 7
Therefore, Breadth is 7m out length (7×3) = 21m.
(25) Solution:- 
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