Explanation

The original sentence is in active voice (present perfect tense).

In passive voice, it becomes "My wallet has been taken away."

Explanation

Diamond is an excellent conductor of heat due to strong covalent bonding and crystal structure.

It is a strong electrical insulator because it lacks free electrons to carry current.

Explanation

The thickness of Earth is about 13,700 kilometers (8,500 miles).

The mantle, which is the biggest part of Earth by volume, is approximately 2,900 kilometers (1,800 miles) thick. 

Explanation

Let's find the selling price (SP) after a 5% discount on the marked price (MP).

MP = Rs. 72,000

Discount = 5% of MP = 0.05 × 72,000 = Rs. 3,600

SP = MP - Discount = 72,000 - 3,600 = Rs. 68,400

The shopkeeper earned a 14% profit on the cost price (CP). Let's denote CP as x.

SP = CP + Profit

68,400 = x + 0.14x

68,400 = 1.14x

Now, find CP:

x = 68,400 / 1.14

x = 60,000

Explanation

Evaluation helps assess effectiveness in teaching and learning by analyzing outcomes and performance.

It provides a basis for discussing success, failure, quality, and areas for improvement in educational processes.

Explanation

Calcium carbonate (CaCO₃) is insoluble in water due to its strong ionic lattice and low solubility product.

In contrast, salts like sodium and potassium compounds are generally highly soluble in water.

Explanation

Given tan θ < 0 and cos θ > 0:

Since cos θ > 0, θ lies in either the 1st or 4th quadrant.

Given tan θ < 0, θ lies in either the 2nd or 4th quadrant.

Combining both conditions, θ must lie in the 4th quadrant.

Explanation

To evaluate the expression, we need to find a common denominator. The least common multiple (LCM) of 9, 8, and 3 is 72.

Let's convert each fraction:

7/9 = (7 × 8) / (9 × 8) = 56/72

6/8 = (6 × 9) / (8 × 9) = 54/72

6/3 = (6 × 24) / (3 × 24) = 144/72

Now, add the fractions:

56/72 + 54/72 + 144/72

= (56 + 54 + 144) / 72

= 254/72

Simplify the fraction:

254/72 = 127/36

Explanation

A number is divisible by 3 if the sum of its digits is divisible by 3.

2+6+5+9 = 22, which is not divisible by 3, so 2659 is not divisible by 3.

Explanation

The correct word is "joyless", not "joyfulless".

"Joyful" already means full of joy, so adding -less to it is incorrect and redundant.