Question

7.
A cuboidal oil tin is 30 cm by 40 cm by 50 cm. Find the cost of the tin required for
making 20 such tins if the cost of tin sheet is Rs 12 per square metre. Also, find the
quantity of oil that these 20 tins can hold.​

Answer 1

Answer:

Step-by-step explanation:

Here, vol. of a cuboid = l×b×h

= 30cm×40cm×50cm

= 60000cm³

area of a cuboid = 2(lb +lh +hb)

= 2(30cm×40cm+40cm×50cm+50cm×30cm)

= 2(120cm²+200cm²+150cm²)

= 2× 470cm² = 940cm²

therefore , to make 20 such tins we have to multiply the SA of a tin with 20

= 940cm²× 20 = 18800cm²

the cost of tin per m²= 12

cost of tin per cm² = 12/100×100 ( 1m2= (100cm)²)

therefore cost of 20 tins = 18800cm² ×12/m²

= 225600cm²

(100cm)²

= 225600cm²

100×100 cm²

= 22.56

now volume of 20 tins = vol of a tin × 20

= 60000cm³ × 20

= 1200000cm³

Thus the oil it can hold is the volume of 20 tins.

You can proceed without finding the SA of 20 tins, where you'd have to multiply with 20 while finding the cost of 20 tins with₹ 12/m²