Exercise 11.5
1. What per cent of
Solution:
(i) 24 is 6?
We have,
=25%
Hence 24 is 6 = 25%
(ii) Rs.125 is Rs.10?
= 8%
Hence, Rs 10 is 8% of Rs 125
(iii) 4km is 160 metres?
Hence, 160 metres of 4km is 4%
(iv) Rs. 8 is 25 paise?
We know that, Rs 1 = 1`00 paise
Therefore Rs. 8 = 800 paise
= 3.125%
Hence 25 paise is 3.125% of Rs. 8
(v) 2 days is 8 hours?
Everyone knows that,
1 day is 24 hour
Hour is 24 hours
(vi) 1 lire is 175 ml
Everyone knows that,
1 lire = 1000 ml
= 17.5%
Hence 175ml is 17.5% of 1 litre
2. What per cent is equivalent to 3/8?
Solution:
= 37.5
3. Find the following:
Solution:
(i) 8 is 4% of which number
Let the required number. Then,
4% of X = 8
X = 200
(ii) 6 is 60% of which number
Let the required number. Then,
60% of x = 6
X = 10
(iii) 6 is 30% of which number
Let the required number. Then,
30% of x = 6
= 20
(iv) 12 is 25% of which number
Let the required number. Then,
25% of X = 12
X = 48
4. Convert each of the following pairs into percentages and find out which is more?
(i) 25 marks out of 30, 35 marks out of 40
Solution:
= 87.5%
Therefore 35 marks out of 40(87.5%) is more than 25 marks out of 30
(ii) 100 runs scored off 110 balls, 50 runs scored off 55 balls
Solution:
= 90.911%
Both are same (90.91%)
5. Find 20% more than Rs.200.
Solution:
We have
Therefore 20% more than Rs.200 = Rs. 200 + Rs.40
= Rs. 240
6. Find 10% less than Rs.150
Solution:
We have
Therefore Rs. 150 Less than Rs. 150 = Rs. 150 + Rs. 15
= Rs. 135