Question

Man our adds a 65% innt juice tolutlun to 15 matters of a drink that is 10% fruit pice. llow much of the 65% fruit juicesolution must be added to create a fruit Panch that is 35% fruit juice? 4. FLYING The speed of the wind is 20 miles per hour. Ifit takes a plane 7 hours to fly 2368 miles round rip, determine the plan's speed in sill ili SA. It took Adnan and Tarek 6 hours to rake the leaves together last year. The previous year it took Tarek 10 hours to do it alone. How long will it take Adnan if he akes them by himself this year? 58. Omar and Ali paint houses together. If Omar can paint a particular house in 6 days and Ali can paint the same house in 5 days, how long would it take the two of them if they work together?

Answer 1

3) Let x ml of 65% juice be added to 15ml of 10% juice Amount of fruit juice in the solution 0.65x(0.10x15)0.65x 1.5 Percentage of fruit juice in the solution- (0.65x + 1.5)/(x+15) Hence this must be equal to 0.35 0.65x +1.5 =>x= 12.5ml Hence to create a fruit punch of 35% fruit juice, 12.5 ml of 65% fruit juice solution must be added to 15 ml of 10% fruit juice solution Original(ml) Added(ml 8.125 12.5 New(ml) 9.625 27.5 Amount of juice Total solution Amount of juice added - 0.65x12.5 - 8.125ml 4) Let speed in still air be v' miles/hr Speed when along with wind V+20 miles/hr Speed when against wind v-20 miles/hr 1184 1184-7 hrs v+20 v-20 Total time+ 1184 v+20 v-20 ゾー400 1184 => 7V2-2368V-2800-0 Solutions are v-339.46 and -1.17 Negative value is discarded, hence speed in still air = 339.46 miles/hr 5) Let Adnan takes 'b' hours to do the work alone In 1 hour, he completes 1/b amount of work Similarly in 1 hour, Tarek completes 1/10 amount of work In 1 hour, combined work done by them1/b 1/10 Hence 1/b1/101/6 Hence Adnan takes 15 hours to do the work alone 6) This question is somewhat similar to last question >1/b 1/15>b 15 hours Let it takes both of them to paint the house in y days In 1 day, they complete 1y of the work Hence 1/y 1/61/5 y30/11 2.72 days