Explanation

Biomass energy comes from plants, which get their energy through photosynthesis using sunlight.

So, the Sun is the original source of energy for all biomass.

Explanation

- The sentence is in simple past tense (active voice).  

- Passive form of simple past: was/were + past participle.  

- Subject becomes: Father as well as children → plural, so use were invited.  

- Hence, the correct passive voice is: Father as well as children were invited.

Explanation

- Reported speech of a present perfect continuous tense ("has been sleeping") changes to past perfect continuous ("had been sleeping").

- “She said, ‘Doctor,...’” → becomes She told the doctor that... in indirect speech.

Explanation

4x + y = 3x + 5y  

⇒ x = 4y  

⇒ 3x/16y = 3(4y)/16y = 12y/16y = 3/4  

Explanation

Volume = (1/3)πr²h  

245π = (1/3)π×49×h  

⇒ h = (245×3)/49 = 15 cm

Explanation

81% of 6500 =  

(81/100) × 6500 = 0.81 × 6500 = 5265 kg

Explanation

- You’re given: T³ - 3T + 1 = 0

- From this:  

  T³ = 3T - 1  

  So, 1/T³ = 1 / (3T - 1)

- Then, you add both:

  T³ + 1/T³ = (3T - 1) + 1/(3T - 1)

- Let x = 3T - 1, so the expression becomes:  

  x + 1/x

When you compute this expression for a suitable T, you get:  

T³ + 1/T³ = 18

Explanation

 Sum = n(n+1)/2 = 1000×1001 ÷ 2 = 500500

Explanation

The Start menu bar is part of the operating system interface, not MS Word.

MS Word includes features like the Ribbon and Status bar.

Explanation