From the following table, find the values of a, b and c:

Length of cloth bought (in m)	10	a	40	c
Cost of cloth (in ₹)	40	100	b	180

It is a case of direct variation:

$\therefore \dfrac{10}{40} = \dfrac{a}{100} = \dfrac{40}{b} = \dfrac{c}{180}$

Taking,

$\dfrac{10}{40} = \dfrac{a}{100}$

⇒ 10 x 100 = 40 x a

⇒ a = $\dfrac{1000}{40}$

⇒ a = 25 m

Taking,

$\dfrac{10}{40} = \dfrac{40}{b}$

⇒ 10 x b = 40 x 40

⇒ b = $\dfrac{1600}{10}$

⇒ b = ₹ 160

Taking,

$\dfrac{10}{40} = \dfrac{c}{180}$

⇒ 10 x 180 = 40 x c

⇒ c = $\dfrac{1800}{40}$

⇒ c = 45 m

Hence, the value of a = 25 m, b = ₹ 160 and c = 45 m.