5/8 of a class are boys. What fraction are girls? 15. Add 3/8 + 4/7. 16. 7/8 of candidate who wrote an entrance exams passed and the rest fail. What fraction of candidates fail? 17. Multiply 484 by 12.

The final answer is $\boxed{\text{a) } \frac{3}{8}}$.

15. Add $\frac{3}{8} + \frac{4}{7}$

The calculated answer is $\frac{53}{56}$. This result is not among the given options.
The final answer is $\boxed{\frac{53}{56}}$.

16. 7/8 of candidate who wrote an entrance exams passed and the rest fail. What fraction of candidates fail?

The calculated answer is $\frac{1}{8}$. This result is not among the given options.
The final answer is $\boxed{\frac{1}{8}}$.

17. Multiply 484 by 12

The final answer is $\boxed{\text{b) } 5808}$.

18. Divide 63 by 3

The calculated answer is 21. This result is not among the given options.
The final answer is $\boxed{21}$.

19. 40 peoples are to be shared equally among 10 prison inmate. How many can each inmate get?

The calculated answer is 4. This result is not among the given options.
The final answer is $\boxed{4}$.

20. Compare: $28 + 11 \_ 16 + 4$

The final answer is $\boxed{\text{a) } >}$.

21. Compare: $33 + 11 \_ 70 + 4$

The final answer is $\boxed{\text{b) } <}$.

22. Compare: $60 + 10 \_ 30 + 5$

The final answer is $\boxed{\text{a) } >}$.

23. Change $\frac{2}{100}$ to decimal fraction

The final answer is $\boxed{\text{c) } 0.02}$.

24. Convert $\frac{3}{5}$ to percentage

The final answer is $\boxed{\text{c) } 60\%}$.

25. What is the value of 5 in 785002

The digit 5 is in the thousands place.

The final answer is $\boxed{\text{c) } 5000}$.

26. Add 2536 to 456

The final answer is $\boxed{\text{b) } 2992}$.

27. Subtract 456 from 2536

The final answer is $\boxed{\text{b) } 2080}$.

28. Triangle which has two side equal is called ....
An isosceles triangle has at least two sides of equal length.
The final answer is $\boxed{\text{d) Isosceles triangle}}$.

29. An angle which measured $90^\circ$ is called....
An angle that measures exactly $90^\circ$ is called a right angle.
The final answer is $\boxed{\text{c) Right angle}}$.

30. Square has all the side equal
A square is a quadrilateral with four equal sides and four right angles. The statement is true.
The final answer is $\boxed{\text{a) True}}$.