1. Find the volume, the total surface area of a rectangular solid 6 m long, 4.5 m broad and 80 cm high.
2. Find the cost of 8 kg apples, if 7 kg of apples costs 315 rupees.
3. The total surface area of a cube is 726 square cm. Find it's volume.
4. What are rational numbers? Give ten examples.
5. Solve : 3x + 5 = 11.
please solve.........
Answers
Answer:
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Step-by-step explanation:
Q1.
length = 6 m
width = 4.5 m
hieght = 80 cm ,to convert this into cm we will divide =80/100=0.8 m
so the hieght is =0.8 m
solution
volume of a rectangle=length × width ×hieght
V=6×4.5×0.8
V =21.6
Q2.
apples= 7 kg
cost =315 rs
cost of 1 kg apples=x
solution
x= 315÷7
one kg cost =45 rupees
so, 8 × 45 = 360is the cost of 8 kg apples
Total surface area of cube = 6 ( side )²
Q3.
∴ 6 ( side )² = 726
⇒ ( side )² = 726 / 6
⇒ ( side )² = 121
⇒ side = √ 121
⇒ side = 11 cm
Now,
Volume of cube = ( side )³
⇒ Volume = ( 11 × 11 × 11 ) cm³
⇒ Volume = 1331 cm³
Q4.
examples
1. 7/4
2. 1/100
3.1/2
4. 1/11
5. 5/8
6.17/5
7.11/4
8.6/10
9.3/4
10.1/4
Q5.
3x+5=11
3x=11-5
3x=6
x=6/3
x=3