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:
