Elements A and B combine to form two compounds  A2B and A2B3 . When 0.2 moles of A2B  weigh 8.8 grams and 0.05 moles of   A2B3weigh 3.8 grams then the atomic weights of A and B respectively are

0.2 moles of   A2B= 8.8 grams1 mole of  A2B = 44 grams∴ 2A+B = 44 −−(1)0.05 moles of  A2B3 = 3.8 grams1 mole of   A2B3= 76 grams2A+3B = 76−−−(2) Eq(2) –Eq(1)    B = 16Substituting the value of ‘B’ in eq(1)                            2A +16 = 44                                   2A = 28                                     A = 14