Answer: A) CaO Explanation: An ionic bond is a chemical bond between two atoms in which one atom seems to donate its electron to another atom.   Here in the given compounds, the compound that contains ionic bond is CaO, Calcium oxide.

I am History.   Yes, history refers to all the past, but we can create history in the presentand it cannot be polluted in the future.

Answer: C) 2:1 Explanation: Given rate of wheat at cheap = Rs. 2.90/kg Rate of wheat at cost = Rs. 3.20/kg Mixture rate = Rs. 3/kg Ratio of mixture =            2.90                              3.20                               3 (3.20 - 3 = 0.20)            (3 - 2.90 = 0.10)   0.20 : 0.10 = 2:1   Hence, wheat at Rs. 3.20/kg be mixed with wheat at Rs. 2.90/kg in the ratio of 2:1, so that the mixture be worth Rs. 3/kg.

Answer: A) Microsoft Explanation: Microsoft has acquired Flipgrid, an education start-up with an app that lets students record and share videos on specific topics with their classmates.   Microsoft is making Flipgrid free of charge.

Answer: B) June 21 Explanation: The World Music Day is celebrated across the world on 21 June.   The day is also known as 'Fete de la Musique' after a music festival that began in France in 1982.   This Day was first celebrated on 21st June 1982.

Answer: D) Cuba Explanation: Havana is the capital city of Cuba. It's currency is Cuban Peso.

Answer: C) 289 Explanation: Here the given number series is 270, 261, 279, 252, 289, 243 270 - 9 = 261 261 + 18 = 279 279 - 27 = 252 252 + 36 = 288 (not equals to 289) 288 - 45 = 243   Hence, the odd number in the given number series is 289.

Answer: A) 72 km Explanation: Rate of her upstream = 12/2.5 = 4.8 km/hr Then, ATQ Rate of downstream = 4.8 x 3 = 14.4 km/hr   Hence, the distance she covers downstream in 5 hrs = 14.4 x 5 = 72 kms.