Answer: D Concentration of boric acid = 80% =80cc Quantity of water = 20cc Let x cc of water be added to get the concentration of 50% 80/(100+x) = 50/100 x=60cc.
Q. No. 2:
An inspector rejects 0.08% of the metres as defective. How many will he examine to reject 2?
Answer: C Let the inspector examined x metres, then 0.08% of x=2 x*0.08/100 =2 x= 2500
Q. No. 3:
After having spent 35% of the money on machinery, 40% on raw material and 10% on staff, a person is left with Rs 60,000.The total amount of money spent on machinery and raw material is
Answer: B Let the original money be Rs 100. Then, money spent on machinery = Rs 35. Money spent on raw material = Rs 40 Money spent on staff = Rs 10 Money let = 100-85 = Rs 15 If money let is Rs 15, original money =Rs 100 If money left is Rs 60,000, then original money => 100*60,000/15 = Rs 4,00,000 Money spent on machinery and raw material = 4,00,000*75% = Rs 3,00,000.
Q. No. 4:
If 50% of the 2:3 solution of milk and water is replaced with water, then concentration of the solution is reduced by
Answer: C Let the quantity of milk and water be 40 and 60 respectively, after removing 50% of solution quantity of milk =20 and quantity of water =30. Therefore, the concentration of the solution is reduced from 40 to 20 i.e reduced by 50%.
Q. No. 5:
Vishal goes to a shop to buy a radio costing Rs 2568. The rate of sales tax is 7%. He tells the shopkeeper to reduce the price of the radio to such an extent that he has to pay Rs 2568, inclusive of all sales tax. ind the reduction needed in the price of the radio.
Answer: A Let the reduced price of the radio be Rs x. x+ 70% of x =2568 x+ 7*x/10 = 2568 => x=2400 Reduction needed in the price of radio = 2568-2400 = 168.
Q. No. 6:
Avi purchased an office bag with a price tag of Rs 600 in a sale where 25% discount was being offered on the tag price. He was given a further discount of 10% on the amount arrived at after giving usual 25% discount. What was the final amount paid by Avi?