Answer:
B. about 41
A. 11
Step-by-B.step explanation:
Answer:
25%
Step-by-step explanation:
Its basic division really. The easiest way to think of it is how many times can 3 fit into 12 three fits into 12 four times in fraction that's 1/4 or 1 over 4. Just like the quarter (United States quarter) each one is 25 cents and you need 4 of then to make 1 US dollar or 100% so each group of three is 25 percent. This under standing could work with a variety of numbers 5 is what percent of 20 or 7 is what percent of 28 if it comes in 4s each is 25%. Hope this helps.
Answer:
D.
Step-by-step explanation:
1. Answer A:
15 students signed up for violin lessons (4 boys + 11 girls)
15 / 70 = approx. 21% of the class.
Answer A says 28%, so this is incorrect.
2. Answer B:
17 students signed up for drum lessons (11 boys + 6 girls)
17/70 = approx. 24%
B says 17% signed up for drums, so this is incorrect.
3. Answer C.
Wrong because more girls signed up for piano lessons (15 girls, whereas only 9 boys signed up for piano)
4. D. The same percent of boys and girls are taking guitar lessons.
Get the total number of boys and girls in the class (just add the results for each separately for all instruments)
Boys: 11 + 6 + 9 + 4 = 30
Girls: 6+8+15+11 = 40
6 out of 30 boys signed up for guitar
6/30= 20%
8 out of 40 girls signed up for guitar
8/40 = 20%
Answer is D
13 and -3
13+-3=10
13x-3=-39
It's useful in following conditions:
(i) when you want to know the valency to male compounds
for example :
when H2 and O2 react in normal conditions they form H2O, amd here we needed crossmultiplication of their valencies.
(ii) To know masses while calculating mass number.
For example In case you wanna find mass of 100 molecules of H2O.
(iii) To find electronegativity (to determine type of bond formed).
For example: which kind of bond Hydrogen and Clorine will form.
