Question

IF 7KG ONIONS COST ₹140 ,HOW MUCH MUST PAY FOR 12KG ONIONS ??​

Answer 1

Unitary method:-

7 kg = Rs 140

⇒ 1 kg = Rs 140 ÷ 7 = Rs 20

So, for 12 kg = Rs 20 × 12 ⇒ 12 kg = Rs 240

Proportionality concept:-

Let the cost be (r).

x || 7 kg || 12 kg

y || 140 || r

So, it is a case of direct proportion.

⇒ x/y = k (constant) ⇒ 7/140 = 12/r ⇒ 1/20 = 12/r

By cross multiplication,

⇒ r = 12 × 20 ⇒ r = 240.

∴ The cost is 240 ruppees.

Answer 2

Answer:

$\huge \red{ \: Hi \: dear,}$

$\red{Your \: question - }$

$If \: 7 \: kg \: onions \: cost \: 140 \: \\ rupees , \: how \: much \: must \: we \: pay \: \\ for \: 12 kg \: onions.$

$\green{Solution-}$

$Let \: the \: cost \: of \: 12kg \: of \: onions \\ \: be \: x$

$\therefore \: \frac{7}{140} = \frac{12}{x} \\ 7x = 140 \times 12 \\ x = \frac{140 \times 12}{7} \\ x = 20 \times 12 \\ x = 240 \\ \therefore \: The \: cost \: of \: 12kg \: onions \\ \: is \: ₹240$