Exercise 1.5 - Chapter 1 Number Systems Term 3 7th Maths Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

Updated By SaraNextGen

On April 24, 2024, 11:35 AM

Ex $1.5$
Miscellaneous Practice problems
Question $1 .$
Malini bought three ribbon of lengths $13.92 \mathrm{~m}, 11.5 \mathrm{~m}$ and $10.64 \mathrm{~m}$. Find the total length of the ribbons?
Solution:
Length of ribbon $1=13.92 \mathrm{~m}$
Length of ribbon $2=11.50 \mathrm{~m}$
Length of ribbon $3=10.64 \mathrm{~m}$
Total Length of the ribbons $=13.92 \mathrm{~m}+11.5 \mathrm{~m}+10.64 \mathrm{~m}=36.06 \mathrm{~m}$
Totla length of the ribbons $=36.06 \mathrm{~m}$
 

Question $2 .$
Chitra has bought $10 \mathrm{~kg} 35 \mathrm{~g}$ of ghee for preparing sweets. She used $8 \mathrm{~kg} 59 \mathrm{~g}$ of ghee. How much ghee will be left?
Solution:
Total weight of ghee bought $=10 \mathrm{~kg} 35 \mathrm{~g}$
Weight of ghee used $=8 \mathrm{~kg} 59 \mathrm{~g}$
Weight of ghee left $=10.35 \mathrm{~kg}-8.59 \mathrm{~kg}=1.76 \mathrm{~kg}$

$\therefore$ Weight of ghee left $=1 \mathrm{~kg} \mathrm{} 76 \mathrm{~g}=1.76 \mathrm{~kg}$

Question $3 .$
If the capacity of a milk can is $2.53 \mathrm{l}$, then how much milk is required to fill 8 such cans?
Solution:
Capacity of 1 milk can=2.53 I
$\therefore$ Capacity of 8 milk cans $=2.531 \times 8=20.24 \mathrm{l}$
To fill 8 cans $20.241$ of milk is required.

Question $4 .$
A basket of orange weighs $22.5 \mathrm{~kg}$. If each family requires $2.5 \mathrm{~kg}$ of orange, families can share?
Solution:
Total weight of orange $=22.5 \mathrm{~kg}$
Weight of orange required for 1 family $=2.5 \mathrm{~kg}$
$\therefore$ Number of families sharing orange $=22.5 \mathrm{~kg} \div 2.5 \mathrm{~kg}$
$=\frac{22.5}{2.5}=\frac{22.5}{2.5} \times \frac{10}{10}=\frac{225}{25}=9$
$\therefore 9$ families can share the oranges.

Question $5 .$
A baker uses $3.924 \mathrm{~kg}$ of sugar to bake 10 cakes of equal size. How much sugar is used in each cake?
Solution:

For 10 cakes sugar required $=3.924 \mathrm{~kg}$
For 1 cake sugar required $=3.924 \div 10=\frac{3.924}{10}=0.3924 \mathrm{~kg}$
For 1 cake sugar required $=0.3924 \mathrm{~kg}$.
 

Question $6 .$
Evaluate:
(i) $26.13 \times 4.6$
(ii) $3.628+31.73-2.1$
Solution:
(i) $26.13 \times 4.6$
26.13 $\times 4.6=120.198$

Question $7 .$
Murugan bought some bags of vegetables. Each bag weighs $20.55 \mathrm{~kg}$. If the total weight of all the bags is $308.25 \mathrm{~kg}$, how many bags did he buy?
Solution:
Total weight of all bags $=308.25 \mathrm{~kg}$
Weight of 1 bag $=20.55 \mathrm{~kg}$

$\begin{aligned}
\therefore \text { Number of bags } &=\frac{\text { Total weight }}{\text { Weight of } 1 \text { bag }} \\
&=\frac{308.25}{20.55}=\frac{\left(\frac{30825}{100}\right)}{\left(\frac{2055}{100}\right)} \\
&=\frac{30825}{100} \times \frac{100}{2055} \\
\therefore \text { He bought } 15 \text { bags. } &=\frac{308252055}{2055}=\frac{2055}{137}=15
\end{aligned}$

Question $8 .$
A man walks around a circular park of distance $23.761 \mathrm{~m}$. How much distance will he cover in 100 rounds?
Solution:
In 1 round distance covered $=23.761 \mathrm{~m}$
$\therefore$ In 100 rounds distance $=23.761 \times 100$
$=2376.1 \mathrm{~m}$
$\therefore$ In 100 round he covers $2376.1 \mathrm{~m}$.
 

Question $9 .$
How much $0.0543$ is greater than $0.002$ ?
Solution:
Greater number $=0.0543(-)$
Smaller number $=\underline{0.0020}$
                          $=\underline{0.0523}$
$\therefore$ Required answer is $0.0523$

Question $10 .$
A printer can print 15 pages per minute. How many pages can it print in $4.6$ minutes?
Solution.
In 1 minute the pages printed $=15$
In $4.6$ minutes the pages printed $=15 \times 4.6$
$=69$

Challenge
Question $1 .$
The distance travelled by Prabhu from home to Yoga centre is $102 \mathrm{~m}$ and from Yoga centre to school is $165 \mathrm{~m}$. What is the total distance travelled by him in kilometres (in decimal form)?
Solution:

\therefore 267 \text { metres }=\frac{267}{1000} \mathrm{~km}=0.267 \mathrm{~km}

$\therefore$ Total distance travelled $=0.267 \mathrm{~km}$

Question $2 .$
Anbu and Mala travelled from $\mathrm{A}$ to $\mathrm{C}$ in two different routes. Anbu travelled from place A to place $B$ and from there to place C. A is $8.3 \mathrm{~km}$ from $B$ and B is $15.6 \mathrm{~km}$ from C. Mala travelled from place $\mathrm{A}$ to place $\mathrm{D}$ and from there to place $\mathrm{C}$. $\mathrm{D}$ is $7.5 \mathrm{~km}$ from $\mathrm{A}$ and $\mathrm{C}$ is $16.9 \mathrm{~km}$ from $\mathrm{D}$. Who travelled more and by how much distance?
Solution:

Distance travelled by Anbu:
From place $\mathrm{A}$ to place $\mathrm{B}=8.3 \mathrm{~km}$
Distance from place $\mathrm{B}$ to place $\mathrm{C}=15.6 \mathrm{~km}$
$\therefore$ Total distance travelled by Anbu $=8.3+15.6$
$=23.9 \mathrm{~km}$
Distance travlled by Mala:
Distance travelled place A to $\mathrm{D}=7.5 \mathrm{~km}$
Distance from place $D$ to place $C=16.9 \mathrm{~km}$
Total distance travelled by mala $=(7.5+16.9) \mathrm{km}=24.4 \mathrm{~km}$
$24.4>23.9$
$\therefore$ Mala travelled more distance. She travelled $(24.4-23.9) \mathrm{km}$ more i.e she travelled $0.5 \mathrm{~km}$ more
 

Question $3 .$
Ramesh paid $₹ 97.75$ per hour for a taxi and he used 35 hours in a week. How much he has to pay totally as taxi fare for a week?
Solution:
Payment for the taxi for an hour $=₹ 97.75$
Total hours the taxi was used $=35$ hrs
$\therefore$ Total payment for the taxi for the week

$$
\begin{aligned}
&=97.75 \times 35 \\
&=3421.25
\end{aligned}
$$
Total payment for a week $=₹ 3421.25$

Question $4 .$
An Aeroplane travelled $2781.20 \mathrm{kms}$ in 6 hours. Find the average speed of the aeroplane in $\mathrm{Km} / \mathrm{hr}$.
Solution:
In 6 hours the distance travelled $=2781.20 \mathrm{~km}$
In 1 hour the distance travelled $=\frac{2781.20}{6} \mathrm{~km}$
$\begin{aligned}
&=\frac{(278120 / 100)}{(6 /1)}=\frac{278120}{100} \times \frac{1}{6} \\
&=\frac{278120}{6} \times \frac{1}{100}=46353 \times \frac{1}{100} \\
&=463.53 \mathrm{~km}
\end{aligned}$

Question $5 .$
Kumar's car gives $12.6 \mathrm{~km}$ mileage per litre. If his fuel tank holds $25.8$ litres then how far can he travel?
Solution.
Distance travelled with 1 litre fuel $=12.6 \mathrm{~km}$
$\therefore$ with $25.8$ litres distance travelled $=12.6 \times 25.8$
$=325.08 \mathrm{~km}$
Average speed of the aroplane $=463.53 \mathrm{~km} / \mathrm{hr}$.