Number series (next term): Alternating differences doubling in magnitude with sign flip. Given sequence: 563, 647, 479, 815, ? Find the next number using the alternating ± pattern on differences. Choose the correct value.

Given data563, 647, 479, 815, ?

Concept/ApproachExamine successive differences; they alternate sign and double in magnitude.

Step-by-step calculation647 − 563 = +84479 − 647 = −168 = −2×84815 − 479 = +336 = +2×168Next difference = −672 = −2×336Missing term = 815 − 672 = 143

VerificationPattern holds: +84, −168, +336, −672 (×2 each time, signs alternate).

Final Answer143