Notes Questions Answers

Q. In a house, four bulbs each of 60 watt glow for 5 hrs and an electric heater of 1200 watt is used 2 hrs every day. If the minimum charge upto 20 units is Rs. 80 and the charge for 21 units to 250 units is Rs. 7.30/unit, calculate the cost of electricity consumed in a month.

noreply@blogger.com (Bibek Raj Magar) — Sat, 08 Jul 2017 03:34:00 +0000

Soln:

For 4 bulbs:

Power = 4 * 60 = 240 = 0.24 kw

Time = 5 hrs

Power consumption (PC1) = 0.24 * 5 = 1.2 kwhrs

For electric heater:

Power = 1200 watts = 1.2 kw

Time = 2 hrs

Power consumption (PC2) = 1.2 * 2 = 2.4 kwhrs

Total power consumption in a day = PC1 + PC2 = 1.2 + 2.4 = 3.6 kwhrs

Total power consumption in a month (30 days) = 3.6 * 30 = 108 kwhrs (unit)

The charge up to 20 units = Rs. 80

No. of extra units = 108 - 20 = 88

The cost of 88 units = 88 * 7.30 = Rs. 642.4

Total cost of electricity consumed in month = Rs. 642.4 + Rs. 80 = Rs. 722.4 Ans.

Q. Find unknown sizes of the angles.

noreply@blogger.com (Bibek Raj Magar) — Fri, 07 Jul 2017 03:30:00 +0000

Soln:

<PQR = <QRS [∵ PQ || RS, being alternate angles]

or, y = 2x

From r PQR,

<PQO + <OPQ = <POR

[∵ an exterior angle of a triangle is equal to the sum of the opposite interior angles.]

[Some books prefer to write: External property of a triangle]

x + y = 87⁰

x + 2x = 87⁰

x = 29⁰

y = 2x = 2 * 29⁰= 58⁰

and 2x = 2 * 29⁰ = 58⁰

Hence, <SPQ = 29⁰, <PQR = 58⁰ and <SRQ = 58⁰

Q. If a man runs around a square field of area 8100 m^2 10 times in 30 minutes, find his speed in meter per second.

noreply@blogger.com (Bibek Raj Magar) — Fri, 07 Jul 2017 01:59:00 +0000

Soln:

Area of square = 8100 m²

or, l²= 8100 m²

or, l² = 90²

\ l = 90m

Perimeter of square = 4l = 4 * 90 = 360m

The number times he runs = 10

In 1 time, he runs 360m.

In 10 times, he runs = 360 * 10 = 3600m.

So, distance travelled (d) = 3600m

Time taken (t) = 30mins = 30 * 60 = 1800sec

Speed = d/t = 3600/1800 = 2 m/s Ans.

Q. The minimum charge of telephone per month upto 100 calls is Rs 180 then the cost is Rs 3 per call of 4 minutes. A family paid Rs 1188 as telephone charge including 10% VAT. Find the total number of calls made.

noreply@blogger.com (Bibek Raj Magar) — Thu, 06 Jul 2017 04:39:00 +0000

Soln:

Here, the minimum charge for 100 calls = Rs 180

Let the charge for telephone calls without VAT = Rs x

So, x + 10% of x = 1188

(11/10)*x = 1188

x = 1080

Now, charge for extra calls = Rs 1080 - Rs 180 = Rs 900

Then, the number extra calls = Rs 900 / Rs 3 = 300

Hence, total number calls = no. of minimum calls + no. of extra calls = 100 + 300 = 400.

Note: I assume that duration of each call is 4 minutes, which is not mentioned in the question, I think duration of a call should be given in the question. If you find anything wrong, comment below and do let me know.

Q. The minimum charge of telephone call upto 175 calls is Rs 200 and for each additional call is Re. 1. If a man paid Rs. 328.90 with 10% VAT of his one month telephone bill, find how many extra calls of that month were made?

noreply@blogger.com (Bibek Raj Magar) — Thu, 06 Jul 2017 03:49:00 +0000

Soln:

Here, the minimum charge of 175 calls = Rs 200

Let, the charge of telephone calls without 10%VAT = Rs x.

x + 10% of x = Rs 328.90

(11/10)*x = Rs 328.90

x = Rs299

Now, the charge for extra calls = Rs 299 - Rs 200 = Rs 99

The rate of cost of each extra call = Re 1

Therefore, the number of extra calls = 99/1 = 99

So, the required number of extra calls is 99.

Hello World....

noreply@blogger.com (Bibek Raj Magar) — Sat, 01 Jul 2017 05:27:00 +0000

Hello everyone. This is my first post on http://notesquestionanswer.blogspot.com where we will discuss on various questions from academic levels under the universities of Nepal, so that we have a platform to share our knowledge and ideas and in mean time all of us are benefited from the online and on air.

Thank you for visiting my blog.