EXERCISE 7.5
1). Write these fraction appropriate as addition or subtraction:
a) 1/5 + 2/5 = 3/5
b) 5/5 − 3/5 = 2/5
c) 2/6 + 3/6 = 5/6
2). Complete the statement given in each figure
a) 3/5 + 3/5 = 6/5
b) 8/8 + 8/8 + 2/8 = 18/8 = 9/4
3). Solve:
a) 1/12 + 1/12
Ans.
= (1+1)/12
= 2/12
= 1/6
b) 8/15 + 3/(15 )
Ans.
= (8+3)/15
= 11 / 15
c) 7/7 − 5/7
Ans.
= 7/7− 5/7
= 2/7
d) 1/22 + 21/22
Ans.
= (1+22)/22
= 22/22
= 1
e) 5/9 + 6/9
Ans.
= (5+6)/9
= 11/9
f) 12/15 − 7/15
Ans.
= (12−7)/15
= 15/15
=1
g) 5/8 + 3/8
Ans.
= (5+3)/8
= 8/8
= 1
h) 3/5 + 4/5
Ans.
= (3+4)/5
= 7/5
i) 1- 2/3 (1= 3/3)
Ans.
= 3/3 − 2/3
= (3−2)/3
= 1/3
j) 1/4 + 0/4
Ans.
= (1+0)/(4 )
= ( 1)/4
k) 0/2 + 0/2
Ans.
= (0+0)/2
= 0/2 = 0
l) 16/5 − 7/5
Ans.
= (16−7)/5
= 9/5
m) 2 1/3 − 12/3
Ans.
= (2×3+1)/3 – (1×3+2)/3
= 7/(3 ) − 5/3
= 2/3
n) 3 −12/5
Ans.
= 15/5 − 12/5
= 3/5
4). Shubham painted 2/3 of the wall space in his room his sister Madhavi helped and painted 1/3 of the wall space. How much did they paint together?
Ans.
Fraction of wall painted by Shubham = 2/3
Fraction of wall painted by Madhavi = 1/3
Total painting done by both = 2/3 + 1/3
= (2+1)/3
= 3/3 = 1
Therefore they painted the complete wall together.
5). Kamlesh brought 3 1/2 kg sugar whereas Anwar brought 2 1/2 kg of sugar find the total amount of sugar brought by both of them.
Ans.
Sugar brought by Kamlesh = 3 1/2
= (3×2+1)/2
= 7/2
Sugar brought by Anwar = 2 1/2
= (2×2+1)/2
= 5/2
Therefore total amount of sugar brought by them is
= 7/2 + 5/2 = (7+5)/2 = 12/2 = 6 kg
6). Fill in the missing fraction:
a)7/10 − _/10 = 3/10
b)8/21 − _ /21 = 5/21
c) _ −3/6 = 3/6
d) _ + 5/27 = 12/27
Ans.
a) 7/10 – 4/10 = 3/10
b) 8/21 – 3/21 = 5/21
c) 6/6 – 3/6 = 3/6
d) 7/27 + 5/27 = 12/27
7). The teacher taught 3/5 of the book, Mahesh revised 1/5 more on his own how much he still has to revise?
Ans.
Fraction of what teacher taught = 3/5
Fraction of what Mahesh revised = 1/5
Total portion he revised = 3/5 + 1/5 = 4/5
Portion left to revise 1- 4/5 = (1×5)/(1×5) – ( 4×1)/(5×1) = (5-4)/5 = 1/5
8. Javed was given 5/7 of basket of oranges. What fraction of oranges has left in the basket?
Ans. Oranges given to Javed = 5/7
Fraction of oranges left = 1- 5/7
= 7/7 – 5/7 = (7-5)/7 = 2/7
The fraction of oranges left in the basket is 2/7