Question

do optional exercises come in maths exam class 10th please tell is 13.5 exercise is very important

Answer 1

Ques.3
We have,
Vol. of cistern=150×120×110 = 1980000cm^3
Vol. of water in cistern=129600cm^3
Vol. of 1 brick=22.5×7.5×6.5 = 1096.875cm^3
Vol. of water absorbed by 1 brick = 1/17 × 1096.875cm^3
Let 'x' be the total no. of bricks. Then,
Vol. of water absorbed by x bricks = n×1/17×1096.875cm^3
Vol. of water left in the cistern =(129600×1/17×1096.875)cm^3
Vol. of cistern= Vol. of water left in cistern + Vol. of bricks
1980000 = 129600-x/17×1096.875
1980000-129600 = x×1096.875-n/17×1096.875
1850400 = 1096.875 (x-x/17)
1850400 = 1096.875×16x/17
1850400 = 17550×x/17
x = (180400×17)/17550
= 1792.41cm^3

Ques. 5
Let l be slant height,
l = 13 cm
Ar. of tin req. to make funnel (S) = CSA of cylindrical portion+CSA of frustum portion
S = 2pie r1h + pie (r1+r2)l
= {2pie×4×10+pie (4+9)×13}cm^2
=(80pie+169pie) cm^3
=249pie cm^2

Answer 2

Step-by-step explanation:

GIVEN

LENGTH = 8m

BREADTH = 6m

HEIGHT = 3m

COST = Rs. 30 per m^3

TO FIND

Cost of digging a custodial pit.

SOLUTION

Volume of a cuboid = base area × height = length × breadth × height = lbh.

So here, we have to find the volume of a cuboidal pit.

So, base area = 8m long & 6m broad = 8×6 = 48

Now,

8m × 6m × 3 m

= 144m^3

Now, we have to find out the cost of the cuboidal pit.

So here, cost = Rs. 30 per m^3 ( given )

144 m^3 × 30 m^3

= 4320m^3

Therefore, the cost of digging a cuboidal pit is

= Rs. 4320 m^3 .

Hope this will help you

thanks for ASKING questions to us

have a nice day AHEAD