Final answer:
The amount in decimals is 0.84 and in percentages is 84%.
Step-by-step explanation:
To find the amount in decimals and percentages, we first divide the number of correct answers (42) by the total number of questions (50) to get the fraction: 42/50. To convert this fraction to a decimal, we divide the numerator by the denominator: 42 ÷ 50 = 0.84. Therefore, the amount in decimals is 0.84.
To convert the decimal to a percentage, we multiply it by 100: 0.84 × 100 = 84%. Therefore, the amount in percentages is 84%.