Question

If 15 enveoleps cost rs11.25 what is the cost of 20 such enveoleps​

Answer 1

Cost of 15 envelope = 11.25

Cost Of 1 Envelope = 11.25/15

Cost of 20 Envelope =

$\frac{11.25}{15} \times 20 \\ \frac{11.25}{3} \times 4 \\ \frac{45}{3} = 15$

Hope it helped you

Mark as the brainliest

Answer 2

$\sf\underline{Step-by-step \: explanation}$

$\bold{Using \: proportion \: method. \: ,}$

● Let the cost be x

● Envelopes : Envelopes : : Cost : Cost

........15......... : . ...20. ....... : :11.25 : x

● Product of extremes = Product of means

● 15x = 11.25 × 20

●

$\tt\dfrac{11.25 \: \times \: 20}{15}$

After cancellation...

Rs. 15

Hence; the cost of 20 envelopes will be,

Rs. 15

$\bold{Unitary \: method,}$

● Cost of 1 envelope = $\tt\dfrac{11.25}{15}$

= Rs. 0.75

● Cost of 20 envelopes = Rs. 0.75 × 20 = 15

● Hence; the cost is Rs. 15

Hence Verified!

Final answer = $\huge{Rs. \: 15}$