Answer:
The puzzle is first add the current two numbers and then add their sum to result obtained in previous step.
Step-by-step explanation:
1 + 4 = 5
2 + 5 = 12
12 is obtained by adding 2 + 5 = 7 and adding the result obtained in previous result which is 5 to 7
⇒ 7 + 5 = 12
Now, 3 + 6 = 21
21 is obtained by first adding 3 + 6 = 9 and the previous result obtained is 12
So adding 12 to 9 ⇒ 12 + 9 = 21
Hence, The puzzle is first add the current two numbers and then add their sum to result obtained in previous step.
Answer:
Grams
Step-by-step explanation:
Mass is the amount of matter present inside a solid. Kilograms and grams are the units to measure mass of an object.
For pencil, the unit to measure its mass is grams. As its mass is less, we can use smaller unit.
Hence, the correct option is (c) "grams"
Answer:

Step-by-step explanation:
2/3 pi radians = 2/3 * 180 = 2 * 60 = 120 degrees
split triangle in half:
30, 60, 90 triangle
1/2 PR= 4 root 3