**New Learning Composite Mathematics SK Gupta Anubhuti Gangal Class 7 Ratio and Proportion and Unitary Method Self Practice 7B Solution**

**(1) Find out whether the following groups of numbers are in proportion or not.**

**(a) 18, 20, 9, 10**

**(b) 21, 6, 35, 10**

**(c) 12, 18, 28, 12**

**(d) 5.2, 3.9, 3, 4**

**(e) 16, 3 1 by 3, 18, 3 3/5**

**(2) Find x in the following proportions.**

**(a) x, 6, 55, 11**

**(b) 16, 18, x, 108**

**(c) 4, x, x, 16**

**(d) 7.5, 15, 5, x**

**(3) Find the fourth proportional to**

**(a) 32, 64, 6**

**(b) 8, 9, 24**

**(c) 1/5, 1/9, 1/10**

**(4) Find the mean proportional between**

**(a) 16 and 25**

**(b) 9 and 1/36**

**(c) 0.01 and 0.81**

**Solution:**

**(5) Find the third proportional to**

**(a) 25, 40**

**(b) 18, 30**

**(c) 3.9, 11.7**

**(6) Show that 5, 25, 125 are in continued proportions.**

**Solution:**

**(7) If the cost of 8 m of cloth is Rs. 600, find the cost of 15 m of cloth.**

**(8) When a man spends 5/9 of his monthly income, he saves Rs. 3600 a month, find his income.**

**(9) After selling 85 copies of a book for every 100 copies printed, a publisher finds that 450 copies are left unsold. How many copies were printed?**

**Solution:**

**(10) A truck requires 108 L of diesel for covering a distance of 594 km. How much diesel will be required by the truck to cover a distance of 1650 km?**

**Solution:**