ANSWER : 2

Explanation : : a+ 1/ a-2 =4 =>a²-2a+1 / a-2 = 4 =>a²-2a+1=4a-8 =>a²-6a+9=0 =>(a-3)²=0 a=3 Now (a-2)²+(1/a-2)² =(3-2)²+(1/3-2)²=1²+1²=2

ANSWER : 15

Explanation : : p=q+5 p²+q²=55 =>(q+5)²+q²=55 q²+10q+25+q²=55 2q²+10q-30=0 q²+5q-15=0 q=-5±√25-4(-15) / 2 =-5±√85 / 2 q=4.22 /2 =2.11 or q=-14.22 /2 =-7.11 p=q+5=7.11 In both cases pq=2.11 x 7.11 =15.0021 =15.

ANSWER : Rs 2125

Explanation : : In 8 years an amount becomes 100% This implies in 8 years simple interest on an amount Rs x.is Rs x. S.I= X x 8 x R / 100 = x R=100 / 8 =12.5 % Compound interest for two years =P[(1+R/100)²-1] =8000[(1+12.5/100)²-1] =8000[(1+1/8)²-1] =8000[(9/8)²-1] =8000[81/64-1] =8000x17/64=Rs.2125

ANSWER : 3.5 km/hr

Explanation : : Speed down stream=15/3=5 km/hr Speed Upstream = 15 / 7 1/2 =2 km /hr Rate in still water = 1/2 (Speed down Stream + Speed Upstream) = 1/2(5+2) =7/2=3.5 km/hr

ANSWER : 6 hrs.12 min

Explanation : : Time taken =Distance /Speed =90/18 =5 hrs Total breaks Quotient of =90/7=12 Total break = 12 x6=72 min = 1 hr.12 min Total time taken = 5hrs.1 hrs.12 min =6 hr.12 min