[Question]Brian has the same percentage of white stones and black stones in his collection of 100 stones as he does of grey stones and green stones in a separate collection. He has 40 grey stones and 60 green stones. How many white stones does Brian have if he has more white stones than black ones?
[Answer]First we must determine the percentage of the grey and green stones. We add the two amounts together, finding 40 + 60 = 100. We then figure out that 40 / 100 = .4, meaning 40 percent of the stones are grey in the second selection. This means that 1.0 - .4 = .6, or 60 percent of the stones are green. Since there are more green stones than grey stones, and the white and black pile have the same percentage, and there are more white stones than black stones, that means there are 60 percent white stones in the first pile. Therefore, to find the number of white stones we multiply 100 * .6 = 60 white stones. The answer is 60.

[Question]Julia has $40. She spends half of her money to buy a new game for her phone. She spends a quarter of what she has left on in-game purchases. How much money does she have left?
[Answer]Julia spend $40 / 2 = $20 on the game. After buying the game, she has $40 - $20 = $20 left. She spent $20 / 4 = $5 on in - game purchases. She has $20 - $5 = $15 left. The answer is 15.

[Question]Miranda wants to buy a pair of heels she saw online. She saved money for 3 months. Her sister heard that she was sad and gave her $50 for her to buy the heels. If she paid $260 in total for the heels, how much money did she save per month?
[Answer]First find the total amount of money she saved: $260 - $50 = $210. Then divide that number by the number of months she saved to find the amount she saved each month: $210 / 3 months = $70 / month. The answer is 70.

[Question]Leo had 400 marbles in a jar. He packed the marbles with ten marbles in each pack, and he gave some of them to his two friends, Manny and Neil.  He gave Manny 1/4 of the number of packs of marbles, Neil received 1/8 of the number of packs of marbles, and he kept the rest. How many packs of marbles did Leo keep?
[Answer]
Leo had 400 / 10 = 40 packs of marbles. He gave Manny 1 / 4 x 40 = 10 packs of marbles. And, Neil received 1 / 8 x 40 = 5 packs of marbles. Thus, Leo. gave a total of 10 + 5 = 15 packs of marbles. Therefore, Leo kept 40 - 15 = 25 packs of marbles. The answer is 25.