Arithmetic operators in Ruby - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of mixed arithmetic operations

What is the output of this Ruby code?

Ruby

result = 10 + 5 * 2 - 8 / 4
puts result

A 24

B 18

C 14

D 12

💡 Hint

Remember the order of operations: multiplication and division happen before addition and subtraction.

Multiplication and division are done first: 5 * 2 = 10, 8 / 4 = 2. Then addition and subtraction: 10 + 10 - 2 = 18. But wait, check carefully: 10 + (5*2) - (8/4) = 10 + 10 - 2 = 18. So correct output is 18.

❓ Predict Output

intermediate

Integer division vs float division

What will this Ruby code print?

Ruby

a = 7 / 2
b = 7 / 2.0
puts a
puts b

A

3.5
3

B

3
3

C

3
3.5

D

3.5
3.5

💡 Hint

Division with integers truncates the decimal part, but with floats it keeps it.

7 / 2 is integer division, so result is 3. 7 / 2.0 involves a float, so result is 3.5.

🔧 Debug

advanced

Identify the error in arithmetic expression

What error does this Ruby code raise?

Ruby

x = 5 + * 3
puts x

A SyntaxError

B TypeError

C NoMethodError

D ZeroDivisionError

💡 Hint

Look carefully at the operator usage between numbers.

The expression '5 + * 3' is invalid syntax because two operators '+' and '*' are adjacent without a number between them.

❓ Predict Output

advanced

Modulo operator behavior

What is the output of this Ruby code?

Ruby

puts -13 % 5

A 2

B -3

C -2

D 3

💡 Hint

Modulo in Ruby always returns a non-negative remainder when the divisor is positive.

In Ruby, -13 % 5 returns 2 because it finds the remainder that makes the result non-negative.

🧠 Conceptual

expert

Result of chained assignment with arithmetic

What is the value of variable 'a' after running this Ruby code?

Ruby

a = b = 10
b += 5
c = a + b

A 5

B 15

C 25

D 10

💡 Hint

Remember that 'a' and 'b' are assigned independently and changing 'b' after does not affect 'a'.

Initially, both 'a' and 'b' are 10. Then 'b' is increased by 5 to 15. 'a' remains 10. So 'a' is 10 after all operations.