WAEC Computer Studies 2021 Paper

Concept:QBASIC evaluates arithmetic expressions according to operator precedence. Exponentiation is done first, then multiplication and division, and finally addition and subtraction.Explanation:Start with the given expression: $5 + 3 * 4 / 2 - 3^2$In QBASIC, the exponent operator ${}^{}$ has the highest priority. So first compute $3^2 = 9$.The expression becomes: $5 + 3 * 4 / 2 - 9$Next, carry out multiplication and division from left to right: $3 * 4 = 12$, then $12 / 2 = 6$.Now the expression is: $5 + 6 - 9$Finally, perform addition and subtraction from left to right: $5 + 6 = 11$, then $11 - 9 = 2$.Thus, the expression evaluates to $2$.Answer:C. $2$