The DAV Class 5 Maths Book Solutions Pdf and DAV Class 5 Maths Chapter 4 Worksheet 9 Solutions of Fractional Numbers offer comprehensive answers to textbook questions.
DAV Class 5 Maths Ch 4 Worksheet 9 Solutions
Question 1.
Solve the following word problems.
(a) Gita has eight marbles. She gave \(\frac{1}{4}\) of them to her younger brother. How many marbles did her brother get?
Solution:
Total marbles = 8
Quantity of marbles given to brother = \(\frac{1}{4}\) of 8.
= \(\frac{1}{4}\) × 8
= 2 marbles
Her brother got 2 marbles.
(b) One plum cake weights \(\frac{3}{4}\) kg . If Mr Ramesh buys five such cakes, how many kilograms of cake did he buy?
Solution:
wt. of plum cake = \(\frac{3}{4}\) kg
No. of cakes bought by Mr Ramesh = 5
wt. of cake he bought = 5 of \(\frac{3}{4}\)
= \(\frac{5 \times 3}{4}\)
= \(\frac{15}{4}\) or 3\(\frac{3}{4}\)
He bought 3\(\frac{3}{4}\) kg of cake.
(c) The cost of one kilogram apples is ₹ 25\(\frac{1}{2}\). What is the cost of 1\(\frac{1}{2}\) kilogram apples?
Solution:
Cost of 1 kilogram apples = 25\(\frac{1}{2}\) = ₹ \(\frac{51}{2}\)
Cost of 1\(\frac{1}{2}\) kilogram apples = \(\frac{51}{2} \times 1 \frac{1}{2}\)
= \(\frac{51}{2} \times \frac{3}{2}\)
= \(\frac{153}{4}\) or ₹ 38\(\frac{1}{4}\).
Cost of 1\(\frac{1}{2}\) kilogram of apples is ₹ 38\(\frac{1}{4}\).
(d) Mr Gupta puts 3\(\frac{1}{4}\) litres of petrol in his car. If he uses \(\frac{1}{3}\) of it, how many litres of petrol did he use?
Solution:
Total quantity of petrol in car = 3\(\frac{1}{4}\) l = \(\frac{13}{4}\) l
He uses quantity of petrol = \(\frac{1}{3}\) of \(\frac{13}{4}\)
= \(\frac{1}{3} \times \frac{13}{4}\)
= \(\frac{13}{12}\) l or 1\(\frac{1}{12}\) l
He use 1\(\frac{1}{12}\) litre of petrol.
(e) Neha spends \(\frac{3}{5}\) hours a day in morning exercises. How many hours does she spend in morning exercises in one week?
Solution:
In one day Neha spent time in morning exercises = \(\frac{3}{5}\) hr
In 7 days Neha spent time in morning exercise = 7 × \(\frac{3}{5}\)
= \(\frac{7 \times 3}{5}\)
= \(\frac{21}{5}\) hrs
= 4\(\frac{1}{5}\) hrs
She spent 4\(\frac{1}{5}\) hours in morning exercises in one week.
(f) The thickness of the Mathematics book of class-V is 1\(\frac{1}{4}\) cm. What will be the thickness of a pile of 16 such books?
Solution:
Thickness of 1 book of Mathematics = 1\(\frac{1}{4}\) cm = \(\frac{5}{4}\) cm
Thickness of 16 books of Mathematics = 16 × \(\frac{5}{4}\)
= \(\frac{16 \times 5}{4}\)
= 20 cm
The thickness of a pile of 16 such books is 20 cm.
Word Problems
Example 1.
Raghu has \(\frac{1}{2}\) kg of toffees. He gives \(\frac{2}{3}\) of it to his sister. How many toffees were given to his sister?
Solution:
Quantity of toffees Raghu has = \(\frac{1}{2}\) kg
Quantity of toffees given to his sister = \(\frac{2}{3}\) of \(\frac{1}{2}\) kg
= \(\frac{2}{3} \times \frac{1}{2}\)
= \(\frac{1}{3}\) kg
Raghu’s sister gets \(\frac{1}{3}\) kg toffees.
Example 2.
In a class of 30 students \(\frac{3}{5}\) are girls. Find the number of girls in that class.
Solution:
Total students = 30
Number of girls = \(\frac{3}{5}\) of 30
= \(\frac{3}{5}\) × 30
= 18
There are 18 girls in the class.