Raven's Progressive Matrices IQ Flashcards

Sofia is a 16-year-old girl. She is her brother's fourth-oldest sibling. When Sofia is twice as old as him, how old will she be?

Answer: 24

This is a classic age riddle where the 'fourth-oldest sibling' is a distractor. The key is that the age difference between Sofia and her brother remains constant. If Sofia is currently 16, and we assume her brother is 4 years old (a common riddle convention when no other age is given and 'fourth-oldest' is mentioned), their age difference is 12 years. When Sofia is 24, her brother will be 12, making her exactly twice his age while maintaining the 12-year difference.

What is the most significant fraction?

Answer: 5/8

To find the most significant fraction, convert each option to a decimal or find a common denominator. 1/2 = 0.5, 3/5 = 0.6, 4/7 ≈ 0.571, and 5/8 = 0.625. Comparing these decimal values, 0.625 (5/8) is the largest, making it the most significant fraction.

One item in the store has a 20% price reduction. How much more must be added to the percentage to reach the original price?

Answer: 25

If an item has a 20% price reduction, its current price is 80% of the original price (100% - 20% = 80%). To return to the original price, you need to add back the 20% that was removed. This 20% represents 1/4 of the current reduced price (20% / 80% = 1/4). Therefore, you must add 25% (1/4 * 100%) to the reduced price to reach the original price.

Five machines can produce five parts in five minutes. How long does it take 100 machines to make 100 parts?

Answer: 5

This is a trick question. If five machines produce five parts in five minutes, it implies that each individual machine produces one part in five minutes. Therefore, if you have 100 machines, and each machine still takes five minutes to produce one part, then 100 machines will collectively produce 100 parts in the same five minutes. The time per part per machine remains constant regardless of the number of machines.

There is a lake with water lilies floating on its surface. Every day, the number of lilies doubles. How long will it take to occupy the lake's floor if it takes 48 days?

Answer: 47

If the number of lilies doubles every day, and the lake is completely covered on day 48, then on the day immediately preceding day 48, the lake must have been exactly half covered. Since the lilies double daily, being half covered on day 47 means it would become fully covered on day 48. Therefore, it takes 47 days for the lake to be half full.

Which number in the pattern should be placed next? 37, 34, 31, 28

Answer: 25

This is an arithmetic sequence where each subsequent number is obtained by subtracting 3 from the previous number. Following this pattern: 37 - 3 = 34, 34 - 3 = 31, 31 - 3 = 28. Therefore, the next number in the sequence is 28 - 3 = 25.

Which number best sums up the comparison? 8:4 as 10:

Answer: 5

The relationship between 8 and 4 is that 4 is half of 8 (8 ÷ 2 = 4). Applying the same proportional relationship to 10, dividing 10 by 2 yields 5. Thus, 8:4 as 10:5 maintains the consistent ratio of the first number being twice the second.