Question : Directions: Some questions are solved based on a certain system. Identify that operation and find the correct answer from the four responses.
a = 14(290)15; b = 16(330)17; c = 18(?)19
Option 1: 300
Option 2: 270
Option 3: 170
Option 4: 370
Correct Answer: 370
Solution :
Given:
a = 14(290)15; b = 16(330)17; c = 18(?)19
Subtract the square of the first number from the square of the third number and multiply the resultant by 10, to get the middle number –
Like, a = 14(290)15→(15
2
– 14
2
) × 10 = (225 – 196) × 10 = 29 × 10 = 290
b = 16(330)17→(17
2
– 16
2
) × 10 = (289 – 256) × 10 = 33 × 10 = 330
c = 18(?)19→(19
2
– 18
2
) × 10 = (361 – 324) × 10 = 37 × 10 = 370
So, 370 is the required missing term. Hence, the fourth option is correct.
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