NCERT Exercise 2.3 Solution
Fractions and Decimals 7th Math
NCERT Exercise 2.3 Solution
Question (1) Find:
(i) `1/4` of (a) `1/4`
Solution :
Given, to find `1/4` of `1/4`
We know that, the word "of" stands for multiplication in mathematics, thus after replacing "of" with sign of multiplication (×), we get
`1/4xx1/4`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(1xx1)/(4xx4)`
`=1/16` Answer
(i) `1/4` of (b) `3/5`
Solution :
Given, to find `1/4` of `3/5`
We know that, the word "of" stands for multiplication in mathematics, thus after replacing "of" with sign of multiplication (×), we get
`=1/4xx3/5`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(1xx3)/(4xx5)`
`=3/20` Answer
(i) `1/4` of (c) `4/3`
Solution :
Given, to find `1/4` of `4/3`
We know that, the word "of" stands for multiplication in mathematics, thus after replacing "of" with sign of multiplication (×), we get
`=1/4xx4/3`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(1xxcancel4)/(cancel4xx3)`
`=1/3` Answer
(ii) `1/7` of (a) `2/9`
Solution :
Given, to find `1/7` of `2/9`
We know that, the word "of" stands for multiplication in mathematics, thus after replacing "of" with sign of multiplication (×), we get
`=1/7xx2/9`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(1xx2)/(7xx9)`
`=2/63` Answer
(ii) `1/7` of (b) `6/5`
Solution :
Given, to find `1/7` of `6/5`
We know that, the word "of" stands for multiplication in mathematics, thus after replacing "of" with sign of multiplication (×), we get
`=1/7xx6/5`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(1xx6)/(7xx5)`
`=6/35` Answer
(ii) `1/7` of (c) `3/10`
Solution :
Given, to find `1/7` of `3/10`
We know that, the word "of" stands for multiplication in mathematics, thus after replacing "of" with sign of multiplication (×), we get
`=1/7xx3/10`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(1xx3)/(7xx10)`
`=3/70` Answer
Question (2) Multiply and reduce to lowest form (if possible):
(i) `2/3xx2 2/3`
Solution :
Given, `2/3xx2 2/3`
`= 2/3 xx 8/3`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(2xx8)/(3xx3)`
`= 16/9`
`=1 7/9` Answer
(ii) `2/7xx7/9`
Solution :
Given, `2/7xx7/9`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(2xxcancel7)/(cancel7xx9)`
`=2/9` Answer
(iii) `3/8xx6/4`
Solution :
Given, `3/8xx6/4`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(3xx6)/(8xx4)`
`=(3xx3xxcancel2)/(8xx2xxcancel2)`
`= 9/16` Answer
(iv) `9/5xx3/5`
Solution :
Given, `9/5xx3/5`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(9xx3)/(5xx5)`
`=27/25`
`=1 2/25` Answer
(v) `1/3xx15/8`
Solution :
Given,` 1/3xx15/8`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(1xx15)/(3xx8)`
`=(1xx5xxcancel3)/(cancel3xx8)`
`=5/8` Answer
(vi) `11/2xx3/10`
Solution :
Given, `11/2xx3/10`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(11xx3)/(2xx10)`
`=33/20`
`=1 13/20` Answer
(vii) `4/5xx12/7`
Solution :
Given, `4/5xx12/7`
Now, to multiply two or more fractions numerator is multiplied with numerator and denominator is multiplied with denominator.
`=(4xx12)/(5xx7)`
`=48/35`
`=1 13/35` Answer
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